Germanium (Ge) Lenses - Infrared Optics - germanium lens
This information allows the appropriate collimating lens to be selected. Thorlabs offers a large selection of black diamond aspheric lenses for the mid-IR spectral range. Since this laser emits at 3.80 µm, the best AR coating is our -E coating, which provides Ravg < 0.6% per surface from 3 to 5 µm. The lenses with focal lengths closest to the calculated value of 3.46 mm are our 390036-E (unmounted) or C036TME-E (mounted) Molded Aspheric Lenses, which have f = 4.00 mm. Plugging this focal length back into the equation shown above gives a final beam diameter of 4.62 mm along the major axis.
Wide angle lenses are popular for landscape and architecture photography where it’s important to capture as much background and scope of the scene as possible. In most cases, wide-angle lenses will give a field of view of 65 degrees or more, giving you more control to get close to a subject without losing elements of the background. There’s also a small subset of wide angle lenses known as ultra-wide angle lenses. These have focal length ranges of 10-15 mm and are used to get very close to a subject and still include a background in view.
The previous generation Interband Cascade Laser used for this measurement emitted CW laser light with a center wavelength of 3.781 µm. Our LDMC20 temperature-stabilized mount held the laser's temperature at 25 °C. The output beam was collimated by a C037TME-E lens located immediately downstream of the laser face. This lens was selected because of its large NA of 0.85 (which helped maximize collection of the emitted light) and because of its AR coating (Ravg < 0.6% per surface from 3 µm to 5 µm). We measured 10 mW of output power after the lens.
Now that you know how to determine the focal length range of a lens and the maximum aperture of your lens, you can understand the basic performance of almost any camera lens. Lenses come in some common focal length sizes which allow you to compare them apples to apples across different brands. It’s helpful to know the basic lens sizes that are common for beginners to own and what type of conditions they’re most useful for.
Sometimes you may find the words MACRO printed on the side of a lens. True macro lenses have at least a 1:1 magnification. Often it’s 2:1 or better (see below for more information about Macro lenses and what types of photography they are best for). Lenses created by the popular manufacturers that create at least life-size images on the camera sensor should have MACRO printed somewhere on the lens.
The tuning range of individual DFB QCLs and ICLs depends greatly on the actual laser device. Each DFB QCL or ICL is a unique device with its own threshold current, rollover current, and spectrum. Since the wavelength and power of DFB QCLs and ICLs change over the tuning range, operating the lasers near the rollover current is not always desirable in spectroscopy measurements, which require specific wavelengths. The driving current and operating temperature of DFB QCLs and ICLs can be adjusted to change the output signal to the desired wavelength and power.
If designing your own mounting solution, note that due to these lasers' heat loads, we recommend that they be secured in a thermally conductive housing with sufficient cooling capacity, either active or passive, to prevent heat buildup. Heat loads for DFB QCLs and ICLs can be up to 38 W. The total heat loads for the Fabry-Perot QCL HHL package can be up to 70 W, although a typical heat load from a Fabry-Perot QCL itself is around 20 W.
In general, these are the categories of focal lengths you’ll find among major camera brands. Below we’ll cover what each of these lens categories is used for in more detail, but this will provide a general idea of the range of focal lengths you might find stamped on your lenses:
Please explain the difference in distance other than mm? between a 300mm and a 400mm. I have a 300 and photograph wildlife. Thinking about buying a 400mm. Is there a much greater advantage? I am having trouble getting the shots I want with 300mm. I take photos strictly for ref. to paint from. Thank you.
Macro (focal lengths vary) Another common lens to find in a photographer’s bag is a macro lens. They are the perfect lens if you find yourself regularly taking close-up shots like flowers, insects, or detailed food photography.
Beginning photographers sometimes glance over the value of a standard lens, preferring to jump right to the effects of a wide-angle or telephoto lens. Yet the performance of standard lenses should not be overlooked. Photos taken with a standard lens are the most natural and can have higher image quality than those taken with a zoom lens. Prime lenses in standard lengths are small, lightweight, and offer a lot of speed over other lenses.
I have found a camera lens at an estate sale and was wondering if you could tell me what the numbers on the lens, 4 8/4 front and 4 8/4 back, mean. The lens is made by Gundlach-Manhatten Optical Co. Rochester N.Y. Since I know nothing about camera lens, I would appreciate your help. Thank you
Conversely, heat in the lasing region can be absorbed by electrons. This boost in energy can scatter electrons away from the path leading down the laser's energy steps. Later, scattered electrons typically lose energy as heat, instead of as photons.
Focusing Motor Type – Sometimes you may also see a series letters (USM, SWM, HSM, etc.) printed somewhere on the lens, or the words “hypersonic” or “ultrasonic.” You’ll especially find this on higher-end or specialty lenses. These are all terms that camera manufacturers use to describe the type of focusing motor in the lens, called a silent wave motor. Sometimes these types of motors are also called hypersonic or ultrasonic. In general, camera manufacturers advertise silent wave motors because they tend to be faster and quieter than the standard focusing motor you’ll find in entry-level lenses.
Telephoto lenses are popular among sports, wildlife, and nature photography. Telephoto lenses allow you to bring the action of these scenes up close in an image. They are less commonly used in portrait, street, and landscape photography because of the potential for distortion and the loss of background when zooming in close to a subject.
When purchasing telephoto lenses, it’s important to select the most speed for the greatest focal length. Speed is especially important here, as stopping wildlife and sports subjects on the move can be difficult to do without introducing blur and noise to the image. Choosing a lens with an aperture of f/4 or larger is best, even if it’s a significant investment.
It’s important to note that the difference in these letters and what words like ‘hypersonic’ means is completely dependent upon the manufacturer. There are no industry standards about silent wave motors in the same way that focal lengths and apertures are standardized among It’s best to read reviews about the lens performance online rather than rely on the motor type alone to describe the quality.
Proper precautions must be taken when handling and using two-tab C-mount, TO Can, D-mount, or high heat load (HHL) lasers. Otherwise, permanent damage to the device will occur. Members of our Technical Support staff are available to discuss possible operation issues.
Thorlabs' LCM100(/M) Liquid Cooled Mount is specifically designed to be used with Thorlabs' HHL laser packages. The LCM100(/M) Mount is capable of dissipating heat loads of >140 W at 25 °C, making it an ideal solution for temperature-controlled operation for all of Thorlabs' HHL lasers. For more details on the LCM100(/M) Liquid-Cooled Mount, please see its web presentation here.
Full Frame vs. Crop Sensor – All major camera manufacturers sell different models of cameras based on the size of the sensor. When you fit your camera lenses to your camera body, you need to make sure that the lens you purchase is compatible with the lens size (full frame vs. crop sensor vs. mirrorless. If you own a full-frame camera, you won’t be able to use a lens built for a crop sensor camera and vice-versa.
The perpendicular and parallel directions are referenced to the plane of incidence, which is illustrated in Figure 1 for a beam reflecting from a surface. Together, the incident ray and the surface normal define the plane of incidence, and the incident and reflected rays are both contained in this plane. The perpendicular direction is normal to the plane of incidence, and the parallel direction is in the plane of incidence.
Macro lenses come in short lengths (good for low light, macro, and some portraits) as well as standard macro lenses (shooting about 9-11 inches away from the subject in good lighting) and telephoto macro lenses (shooting up to 2 feet away). While the focal lengths vary, macro lenses come with a ‘minimum focus distance’ that will indicate the closest you can be and still have the subject clearly in focus.
Because quantum cascade lasers (QCLs) and interband cascade lasers (ICLs) have intrinsically large divergence angles, it is necessary to install collimating optics in front of the laser face, as shown in the Collimation tab. We are frequently asked what beam quality can be reasonably expected once the beam has been collimated. This tab presents an M2 measurement we performed using our previous generation 3.80 µm Interband Cascade Laser.
The 0.85 NA of the collimating lens we used is the largest NA of any lens for this wavelength range that is offered in our catalog. Despite this large NA, we observed lobes in the far field (shown by the figure below) that are consistent with clipping of the laser-emitted light. An ideal measurement would not contain these artifacts.
Data AnalysisPresented to the right are the second-order moment (D4σ) beam widths for the parallel and perpendicular directions as a function of distance from the laser face (denoted as z). Along the parallel direction, we obtained a minimum beam width of 1.5 mm, while along the perpendicular direction, we obtained a minimum beam width of 1.3 mm. The spatial profiles we observed at the two minimum beam width positions, as obtained by the pyroelectric camera, are shown below.
Thorlabs stocks quantum cascade lasers (QCLs) in four packages: a two-tab C-mount recommended for academic and industrial research, D-mount and high heat load packages with horizontal emission intended for OEM applications and system integration, and a Ø9 mm TO can for easy integration into standard mounts. Please see the Handling tab for more tips and information for handling these laser packages. Other packages may be available as custom orders (see the Custom & OEM Lasers tab).
In the case of an aperture range, you’ll find two numbers printed on the lens. For example, you might find f/3.5-5.6 printed on the lens. In this case, depending on the focal length the zoom lens is set at, the maximum aperture will be a range from f/3.5 to f/5.6. In general, the more you zoom the narrower the aperture on the lens.
At our semiconductor manufacturing facility in Jessup, Maryland, we build fully packaged mid-IR lasers and gain chips. Our engineering team performs in-house epitaxial growth, wafer fabrication, and laser packaging. We maintain chip inventory from 3 µm to 12 µm, and our vertically integrated facilities are well equipped to fulfill unique requests.
If designing your own mounting solution, note that due to these lasers' heat loads, the laser must be mounted in a thermally conductive housing to prevent heat buildup. Heat loads for QCLs and ICLs can be up to 70 W, depending upon the wavelength and package. See the Handling tab for additional information.
Since NALens > NALaser, the 390036-E or C036TME-E lenses will give acceptable beam quality. However, by using the FWHM beam diameter, we have not accounted for a significant fraction of the beam power. A better practice is to use the 1/e2 beam diameter. For a Gaussian beam profile, the 1/e2 beam diameter is approximately equal to 1.7X the FWHM diameter. The 1/e2 beam diameter is therefore a more conservative estimate of the beam size, containing more of the laser's intensity. Using this value significantly reduces far-field diffraction (since less of the incident light is clipped) and increases the power delivered after the lens.A good rule of thumb is to pick a lens with an NA of twice the NA of the laser diode. For example, either the 390037-E or the C037TME-E could be used as these lenses each have an NA of 0.85, which a little less than twice that of our IF3800CM2 laser (NA 0.5). Compared to the first set of lenses we identified, these have a shorter focal length of 1.873 mm, resulting in a smaller final beam diameter of 2.16 mm.
The specifications for the laser indicate that the typical parallel and perpendicular FWHM divergences are 40° and 60°, respectively. Therefore, as the light propagates, an elliptical beam will result. To collect as much light as possible during the collimation process, consider the larger of these two divergence angles in your calculations (in this case, 60°).
Thank you for your excellent article, well laid out, clear and concise with no frightening and off putting jargon. My reason for reading was to gain a little knowledge prior to commencing a photography for beginners course and I had a list of about a dozen questions which you answered all but one of them superbly. The one you failed to mention, but in fairness wasnt pertinent to your article was, “What is meant by noise in a picture?”
Heat Build UpLasers are not 100% efficient in forcing electrons to surrender their energy in the form of photons. The electrons that lose their energy as heat cause the temperature of the lasing region to increase.
A fan may serve to move the heat away from the TEC and prevent thermal runaway. However, the fan should not blow air on or at the laser itself. Water cooling methods may also be employed for temperature regulation. Although thermal grease is acceptable for TO can and HHL lasers, it should not be used with two-tab C-mount or D-mount lasers, since it can creep, eventually contaminating the laser facet. Pyrolytic graphite is an acceptable alternative to thermal grease for these cases. Solder can also be used to thermally regulate two-tab C-mount lasers, although controlling the thermal resistance at the interface is important for best results. Solder is not recommended for thermal regulation of D-mount or HHL lasers.
Before you start shopping for new lenses, you’ll want to know before purchasing a lens is what you plan to use it for. A good multi-purpose lens can elevate all types of photography. However, if you plan to shoot flowers, sports, or wildlife you might be better off choosing a more specific lens. Most photographers start to specialize in lenses that match the types of photography they shoot the most.
Laser OperationThese lasers operate by forcing electrons down a controlled series of energy steps, which are created by the laser's semiconductor layer structure and an applied bias voltage. The driving current supplies the electrons.
You may be surprised to know though, that in some cases you may be able to use your old film lenses with a DSLR camera body. Canon has used the same lens mount system since 1987. Nikon’s has been around since 1959. If you have a film lens that dates back around then, you should be able to get it to attach to your camera body.
Pincushion distortion causes horizontal and vertical lines to bend in toward the center of the image and commonly occurs with zoom or telephoto lenses. Barrel ...
Laser Mount CompatibilityThorlabs' LDMC20(/M) C-Mount Laser Mount ships with current and TEC cables for the LDC4005, ITC4001, ITC4002QCL, ITC4005, and ITC4005QCL controllers. To use the LDMC20 with our other controllers, custom cables will be required. For our Ø9 mm TO can QCL we have the LDM90(/M) Laser Mount which is fully compatible with all of the controllers listed in the tables below; however, the mount itself has a limited heat load of 8 W, meaning some QCLs cannot be driven at full power in this mount. If designing your own mounting solution, note that due to these lasers' heat loads, we recommend that they be secured in a thermally conductive housing to prevent heat buildup.
Thank you for sharing information on cameras and lenses for beginners in an easy to understand language. Everything is clear except the difference between full frame vs crop sensor cameras.
A familiar moment for beginning photographers: You’ve opened up your brand new DSLR and are ready to start capturing the world around you. As you attach the lens to the camera, panic ensues: What are all those numbers and letters on the lens? What do they mean? Do I have the right lens for what I need?
Ø9 mm TO CanThe Ø9 mm TO can provides high thermal conductivity, and can be easily integrated into a standard mount for high-power TO can laser diodes. This package incorporates an additional copper disk for added heat dissipation. The additional material makes this TO can thicker than standard; however, the laser is still compatible with all Ø9 mm laser mounts. An AR-coated ZnSe window protects the QCL from dust and debris. The drive voltage and current are supplied through the pins. The emission of the QCL is centered in the TO can.
If you plan to purchase a new camera lens there are some basic lens features that you’ll want to know when you purchase. Understanding these features can help you better understand why two lenses that look similar on the outside might be sold at very different price points. Considering these factors will also help you to make sure you’re comparing apples to apples across different lens brands.
Quantum laserprice
HHL lasers and TO cans are sealed (although the seal is not hermetic), so the laser chip will not be exposed to air. However, similar dust avoidance precautions should be followed for the window on these packages, since the windows are exposed to the atmosphere.
The maximum drive current and the maximum optical output power of QCLs and ICLs depend on the operating conditions, since these determine the heat load of the lasing region.
Thank you so much for this article. I am new to photography and still have a lot to learn but your article helped me to understand a lot about the lenses that came with my starter set up from Canon.
Standard Lenses (35mm to 60 mm) – Lenses that fall between 35 mm and 60 mm focal length are considered ‘standard’ lenses. You may also see them marketed as ‘standard zoom’ or ‘normal’ lenses. Most photographers start with lenses in this focal length range, and they are common as camera kit lenses. Between wide-angle and telephoto lenses, standard lenses are the best at capturing the same scene as the naked eye.
The back face of the C-mount package and the bottom face of the D-mount or high heat load package is machined flat to make proper thermal contact with a heat sink. Ideally, the heat sink will be actively regulated to ensure proper heat conduction. A Thermoelectric Cooler (TEC) is well suited for this task and can easily be incorporated into any standard PID controller. The HHL package incorporates a suitable TEC.
Typically when the new lens version becomes available, the older version will no longer be available from licensed camera retailers. However, you may still be able to purchase the previous version on the used market or from an online retailer that tend to sell the older versions longer. It’s helpful to know the exact lens version you’re using though because information about older versions quickly becomes hard to find. If you’re reading reviews about lens performance from other photographers, be sure you have the exact version as performance and quality may be quite different.
Thorlabs' Quantum and Interband Cascade Lasers (QCLs and ICLs) are composed of multiple quantum well heterostructures and utilize intersubband and interband transitions, respectively, to access the mid-infrared spectral region. They are offered in four packages: a two-tab C-mount, a Ø9 mm TO can, a D-mount, and a high heat load (HHL) package with horizontal emission. The two-tab C-mount and Ø9 mm TO can packages can be easily interfaced to our SM1 lens tubes, 30 mm cage systems, and 60 mm cage systems using the LDMC20 C-Mount Laser Mount or the LDM90 Laser Mount, respectively. The D-mount and HHL packages are intended for OEM applications and systems integration. The HHL package can be mounted Thorlabs' LCM100(/M) Liquid-Cooled Mount for added thermal regulation and protection of the laser diode. Additional information is available in the Packages tab.
Download the perfect fibre optic pictures. Find over 100+ of the best free fibre optic images. Free for commercial use ✓ No attribution required ...
Depending on the type of lens that you own, the focal length will either be listed as a range of numbers (e.g. 18-55 mm) or one number 50 mm. The difference between a focal length range and fixed focal length will indicate if your lens is a zoom lens or a prime lens.
As shown by the graph above and to the right, we observed significant astigmatism in the collimated beam: the beam waist of the parallel direction occurred around z = 300 mm, while the beam waist of the perpendicular direction occurred around z = 600 mm. This astigmatism corresponds closely to what is expected for this laser, given that the IF3800CM2 laser is specified with a parallel FWHM beam divergence of 40° and a perpendicular FWHM beam divergence of 60°.
Tuning ExampleTo demonstrate the tunability of these lasers, we measured the center wavelength of a previous-generation QD4580CM1 DFB QCL as a function of drive current, from threshold to near rollover, at 15 °C and 25 °C. Over the entire temperature and drive current range, we obtained center wavelengths from 4.568 µm to 4.586 µm (2189.14 cm-1 to 2180.77 cm-1), spanning a range of 18 nm (8.37 cm-1), with output power ranging from 3.2 mW (at threshold current) to 39.1 mW (at near-rollover current). Since the laser is capable of operating at 35 °C, even broader wavelength tuning is also achievable.
Distributed Feedback LasersDistributed feedback (DFB) quantum and interband cascade lasers emit at a well-defined center wavelength and provide single transverse mode operation. By tuning the input current and operating temperature, the output frequency can be tuned over a narrow range between 1 cm-1 and 5 cm-1. They are ideal for chemical sensing (see the Spectroscopy tab), optical communications, and other applications. The output spectrum, power, and L-I-V curve of each serial-numbered device, as measured by an automated test station, are available below and are also included on a data sheet with the laser. These quantum and interband cascade lasers are specified for CW output. While pulsed output is possible, this application prohibits current tuning, and performance is not guaranteed. For two-tab C-Mount and D-Mount lasers, some optical power is emitted through the rear facet; this output is not usable in applications.
Distributed feedback and Fabry-Perot HHL lasers are compatible with any HHL mount, although cables for HHL packages are typically not rated for the 4.5 A maximum current of the distributed feedback lasers' or the up to 8 A maximum current of the Fabry-Perot lasers' internal thermoelectric coolers. For stable mounting and temperature control of HHL lasers, we recommend using the LCM100(/M) liquid-cooled mount and the CAB4007A or CAB4007B dual LD / TEC connector cables. D-mount lasers require custom mounts. Our ICLs emit a horizontally polarized beam at wavelengths as long as 3.5 µm, while our QCLs emit a vertically polarized beam at wavelengths as long as 11 µm.
All lenses have a maximum aperture printed on them in the f/x.x format. This refers to the maximum size of the aperture possible with that particular lens. Prime lenses have one fixed maximum aperture. Zoom lenses can have a fixed maximum or they can have a range of maximum apertures. Fixed maximum ranges on zoom lenses tend to be more expensive, it’s more common to have an aperture range.
Quantum laserhair removal
This handheld magnifier is perfect for pocket or purse.
There are two types of lenses: zoom lenses and prime lenses. Zoom lenses allow you to capture a range of focal lengths using the same lens. Prime lenses—also called fixed lenses—can only capture one focal length. To determine if your lens is a zoom lens or a prime lens, simply look at the focal length numbers on the camera lens.
The most common source of polarized light is a laser. Depending on how the electric field is oriented, we classify polarized light into three types of ...
Motic is a manufacturer of compound microscopes and digital microscopy solutions. MoticEurope is the European Headquarter and Distribution Centre, ...
The CAB4007B Dual Laser / TEC Connector Cable is designed to be used with any of Thorlabs' HHL laser packages or other HHL lasers with compatible pin settings. The CAB4007B connector cable is rated for up to 10 A of laser and TEC current. The CAB4007A Dual Laser / TEC Connector Cable is designed for use with the LCM100(/M) Mount and is rated for up to 11 A of laser and TEC current. For more details on the CAB4007x cables please see the full web presentation here. Please note that third party cables for these packages are typically not rated for the maximum current of the internal thermoelectric cooler.
The same applies to lens filters, remote shutter releases, and external flash. Many of these camera accessories are exclusive to the brand of lens and are not interchangeable. It’s important to review your manufacturer’s guide to determine compatibility with camera accessories.
Some entry-level lens kit will attempt to sell that your zoom lens functions as a macro. However macro lenses provide the best magnification and image quality without distortion. look for MACRO printed on your lens for true macro technology.
DFB QCLs and ICLs are ideal for use in photoacoustic spectroscopy, a technique based on the photoacoustic effect that is able to accurately detect trace gas concentrations for a wide variety of applications. Thorlabs offers an Acoustic Detection Module that can be used with our DFB QCLs and ICLs to build custom QEPAS sensors that target the absorption of a specific gas. We also offer a Quartz-Enhanced Photoacoustic Sensor that targets a methane absorption line to detect trace amounts of methane in a gas.
High Heat Load Package with Horizontal EmissionThis package offers an industry-standard pinout and package dimensions. Each package incorporates a built-in thermistor and thermoelectric cooler (TEC) for active temperature management and prolonged laser lifetime, and also includes an internal aspheric lens that collimates the laser's output. As measured from the bottom of the package, the emission height is 12.7 ± 0.13 mm. The emitted light is coupled out of the package through a wedged zinc sulfide (ZnS) window. The output beam of the Distributed Feedback lasers will deviate downward from the normal by either 2.0° ± 1.5° or 2.0° ± 0.75°, while the output beam of the Fabry-Perot lasers will deviate downward from the normal by 2.0° ± 0.6° or 2.0° ± 0.75°. Each laser is electrically isolated from its mount. More information is available at its Distributed Feedback and Fabry-Perot web presentations.
Use a Current Source Specifically Designed for LasersThese lasers should always be used with a high-quality constant current driver specifically designed for use with lasers, such as any current controller listed in the Drivers tab. Lab-grade power supplies will not provide the low current noise required for stable operation, nor will they prevent current spikes that result in immediate and permanent damage.
While it may be tempting to switch lens brands when you upgrade equipment or when you see a good sale on lenses, there’s no way to interchange a Canon lens with a Nikon lens. The camera kits mount completely different and are not compatible. There are third-party lenses that are compatible with either Canon or Nikon lenses. However, these still are not interchangeable between brands. To date, there is no such thing as a ‘universal’ lens mount.
Interlocks are circuits that stop the laser beam if some condition is not met, such as if the laser casing or a room door is open. Class 3B and 4 lasers ...
One of the biggest distortion concerns with macro lenses is called chromatic aberration. It’s a technical term to describe the ‘halo’ of purple/yellow coloring that occurs on the fringe of subjects in macro photos. With careful composition and some post-processing techniques, it’s possible to correct this, but you’ll want to read performance reviews before purchasing Macro lenses to be sure you’ll be getting the highest quality image possible.
The electric fields of the perpendicular and parallel components oscillate in planes that are orthogonal to one another. The electric field of the perpendicular component oscillates in a plane perpendicular to the plane of incidence, while the electric field of the parallel component oscillated in the plane of incidence. The polarization of the light beam is the vector sum of the perpendicular and parallel components.
Thermally Regulate the LaserTemperature regulation is required to operate the laser for any amount of time. The temperature regulation apparatus should be rated to dissipate the maximum heat load that can be drawn by the laser. For our two-tab C-mount or TO can quantum cascade lasers, this value can be up to 18 W. The LDMC20(/M) C-Mount Laser Mount, which is compatible with our two-tab C-mount package, is rated for >20 W of heat dissipation. The LDM90(/M) Ø9 mm TO Can Laser Mount is only rated for 8 W of heat dissipation, so it cannot operate some quantum cascade lasers at full power. Our DFB D-mount laser's maximum heat load is 7.2 W, our FP D-mount lasers' maximum heat load is 35 W, our HHL FP QCLs have a max heat load of 70 W, and our HHL DFB QCLs and ICL have a maximum heat load of 38 W. The LCM100(/M) Liquid-Cooled Mount is compatible with all standard HHL packages and is capable of dissipating up to 140 W of heat at 25 °C.
Lens diameter is measured in millimeters just like focal length. Ø 77 mm and Ø 82 mm are the two most common lens diameters. Be sure to have this number handy when you purchase filters online. Many filters are advertised based on the camera body, when in fact you should ensure they fit the diameter of your camera lens.
Distributed Feedback Quantum and Interband Cascade Lasers (DFB QCLs and ICLs) offer many attractive features for spectroscopy. They emit at a single wavelength within the mid-IR, where many gaseous species characteristically absorb. Moreover, their emission wavelength is easily tuned (typical tuning range: 1 - 5 cm-1) by changing the drive current and operating temperature of the laser, making them ideal for isolating narrow gas absorption lines. Finally, quantum cascade lasers offer relatively high output power (typically 40 - 120 mW at rollover current), helping improve measurement sensitivity. ICLs will typically have a low output power, but a far lower power consumption.
Lens Version – Some lenses will be printed with a number or letter system indicating which version of the lens you have. For example, a lens that has a “II” listed at the end of the lens name indicates that it’s the second version of that same lens model. It has the same focal length and maximum aperture as the first model but is an ‘improved’ version with higher-quality features. It’s essentially the same as how software developers use the “v2.0” terminology. You may even find “III” lenses, however third iterations of the same lens are rare.
Another item you may find stamped on your lens is image stabilization technology. Each camera manufacturer handles image stabilization slightly differently. Some camera bodies have built in stabilization so the lens doesn’t need to provide stability. Others rely on the lens to provide stabilization. If your camera body does not have it built in, you’ll want to confirm that your lens has image stabilization technology by looking for letters printed on the lens.Unfortunately, the common camera manufacturers abbreviate and market their image stabilization differently. There’s no common set of letters that are used across brands like Canon, Nikon and Sony to indicate image stabilization in the lens. Below are the abbreviations for the common lens brands:
Each Fabry-Perot quantum and interband cascade laser has an HR-coated back facet. As a custom option, these lasers can be ordered with an AR coating on the front facet; however, the custom item will operate as a gain chip and not as a CW laser. Although these lasers are specified for CW output, they are compatible with pulsed applications provided that the CW max operating current is not exceeded. For more information or to order a Fabry-Perot QCL or ICL with a tested and specified pulsed optical power or other custom features, please contact Tech Support.
Currently you have JavaScript disabled. In order to post comments, please make sure JavaScript and Cookies are enabled, and reload the page. Click here for instructions on how to enable JavaScript in your browser.
Telephoto Lenses (70 mm or longer) — Lenses that are 70 mm or longer are known as telephoto lenses. Beyond kit lenses, this is often where beginning photographers invest in their first lens. Telephoto lenses are most often zoom lenses, giving you a wide variety of focal lengths to shoot with. Popular ranges include 70-200 mm, 80-400 mm, 70-300 mm. Telephoto lenses compress distance, making subjects look closer than they are to the naked eye.
Carefully Make Electrical ConnectionsWhen making electrical connections, care must be taken. The flux fumes created by soldering can cause laser damage, so care must be taken to avoid this.
Thorlabs' DFB QCLs emit at wavelengths that range from 4.00 to 11.00 µm (2500 cm-1 to 909 cm-1), while our DFB ICLs emit at wavelengths that range from 3.00 to 3.50 µm (3333 cm-1 to 2857 cm-1). If we do not stock the wavelength required for your application, custom wavelengths are available by contacting Tech Support.
Measured in millimeters, focal length is the not the length of the lens, but how much of the scene will be in focus (angle of view) and the magnification (how large it will be relative to the original). Smaller numbers equate to shorter focal lengths and lower magnification. Larger numbers indicate a narrower angle of view and higher magnification or zoom.
The light vs. driving current (L-I) curves measured for quantum and interband cascade Lasers (QCLs and ICLs) include a rollover region, which is enclosed by the red box in Figure 2.
The 3D display shows the actual shape of the beam. It is possible to easily zoom, pan and rotate the image. The very useful reset button allows to put the data ...
Use the tables below to select a compatible controller for our MIR lasers. The first table lists the controllers with which a particular MIR laser is compatible, and the second table contains selected information on each controller. Complete information on each controller is available in its full web presentation. We particularly recommend our ITC4002QCL and ITC4005QCL controllers, which have high compliance voltages of 17 V and 20 V, respectively. Together, these drivers support the current and voltage requirements of our entire line of Mid-IR Lasers.
Super-telephoto/Ultra-telephoto Zoom Lens (greater than 300mm) — If you plan to spend a majority of your time shooting sports and wildlife photography, you may consider investing in an ultra-telephoto lens. These are a sub-set of telephoto lenses that have focal lengths of at least 300-400 mm. Considered a ‘specialty lens’ ultra-telephoto lenses are high-priced, but allow photographers to clearly focus on subjects far in the distance.
When comparing lenses, the two most important numbers are the focal length range and lens speed. Focal length range will be listed as XX-XX before the letters mm, (e.g. 18-55 mm). Lens speed or maximum aperture will be listed as some number immediately following the letter f. (e.g. f/2.8). Let’s break apart what both focal length range and maximum aperture mean for your own lenses.
Thankfully, the manufacturers know this and each lens should be printed with a set of letters that match the same letters of your camera body to indicate compatibility. Below are the abbreviations for full-frame vs. crop sensor for the most common camera brands:
QuantumCascadelaserprice
The apparatus we used to determine M2 is shown schematically in the figure above. In order to ensure that our results were rigorous, all data acquisition and analysis were consistent with the ISO11146 standard.
A temperature controlled mount is typically necessary to help manage the temperature of the lasing region. But, since the thermal conductivity of the semiconductor material is not high, heat can still build up in the lasing region. As illustrated in Figure 3, the mount temperature affects the peak optical output power but does not prevent rollover.
UV lamps are commonly used for curing coatings and encapsulants. UV provides a rapid, on-demand cure which can help improve and speed up curing processes.
Beginning photographers should spend some time learning about the focal lengths of the lenses they own. Focal length can dramatically impact the perspective of an image and contributes to composition in ways you should be familiar with. To explore the focal length of your camera, try this exercise:
As with image stabilization, every camera manufacturer advertises and markets their own type of silent wave motor. You’ll see different abbreviations for each of the major brands. Below are the silent wave motor abbreviations for the common lens brands:
More details are available on the Custom & OEM Lasers tab. To inquire about pricing and availability, please contact us. A semiconductor specialist will contact you within 24 hours or the next business day.
High-Power Fabry-Perot QCLsFor Fabry-Perot lasers, we can reach multi-watt output power on certain custom orders. The available power depends upon several factors, including the wavelength and the desired package.
Mounts, Drivers, and Temperature ControlFor two-tab C-mount quantum cascade lasers, we generally recommend the LDMC20 C-Mount Laser Mount and ITC4002QCL or ITC4005QCL Dual Current / Temperature Controller. This device combination includes all the necessary components to mount, drive, and thermally regulate a two-tab C-mount laser. Other compatible current and temperature controllers are listed in the Drivers tab. The LDM90(/M) Laser Mount along with the ITC4002QCL or ITC4005QCL can be used with the TO can lasers, but the 8 W cooling capacity of the LDM90 may limit the driving current of the lasers.
Since the output of our MIR lasers is highly divergent, collimating optics are necessary. Aspheric lenses, which are corrected for spherical aberration, are commonly chosen when the desired beam diameter is between 1 - 5 mm. The simple example below illustrates the key specifications to consider when choosing the correct lens for a given application. Please note that lasers in a high heat load (HHL) package are already collimated using a lens integrated into the package.
Although soldering to the leads of our HHL lasers is possible, we generally recommend using cables specifically designed for HHL packages. Thorlabs' CAB4007B LD / TEC cable is specifically designed to connect any standard 10-pin HHL laser package directly to the ITC400xQCL series of laser diode and TEC controllers. The CAB4007A LD / TEC cable can be used to connect an ITC400xQCL controller directly to the LCM100(/M) mount. Please note that third-party cables for high heat load packages are typically not rated for the 4.5 A maximum current of the distributed feedback lasers' or the up to 8 A maximum current of the Fabry-Perot lasers' internal thermoelectric coolers. If soldering to the leads on an HHL package, the maximum soldering temperature and time are 250 °C and 10 seconds, respectively.
Some camera lenses have the diameter of the lens printed on it using the diameter symbol “Ø”. This refers to the diameter of the end of the lens and is helpful when purchasing filters for the camera. When you purchase filters, you’ll need to make sure that they are large enough to cover the full lens or the correct diameter for circular screw-on filters.
Zoom lenses will be printed with the range of focal lengths, but they will also have a focal length guide along part of the zoom ring. It should appear as a series of increasing numbers with a line that moves up and down as you increase or decrease the zoom. The line indicates the exact focal length you are shooting at between the minimum and maximum focal length range.
Once you’ve done the exercise with stationary objects, move outdoors and attempt the same exercise with an object at a further distance or a landscape. It’s the best way to learn more about focal length and the lenses you own.
Standard lenses are considered ‘general purpose’ lenses because they can be used for all types of photography. They are common for portraits and large group photos, street photography and any situation where you’re photographing with the flexibility to move around and get the best angle to shoot from.
When polarized light is incident on a surface, it is often described in terms of perpendicular and parallel components. These are orthogonal to each other and the direction in which the light is propagating (Figure 1).
2023522 — For interchangeable lens cameras produced by Sony, there are two types of mount standard: A-mount and E-mount. The mount is the part that ...
The rollover region includes the peak output power of the laser, which corresponds to a driving current of just under 500 mA in this example. Applying higher drive currents risks damaging the laser.
Fabry-Perot LasersFabry-Perot quantum and interband cascade lasers exhibit broadband emission in a range spanning roughly 50 cm-1 to 120 cm-1. The laser's specified output power is the sum over the full spectral bandwidth. Since these lasers have broadband emission, they are well suited for medical imaging, illumination, and microscopy applications. The output spectrum and L-I-V curve of each serial-numbered device, measured by an automated test station, are available below and are also included on a data sheet that ships with the device.
Thorlabs manufactures custom and OEM quantum cascade lasers in high volumes. We maintain a broad chip inventory at our Jessup, Maryland laser manufacturing facility and we are accustomed to fulfilling specialized requests.
Operating Limits are Determined by the Heat LoadIdeally, the slope of the L-I curve would be linear above the threshold current, which is around 270 mA in Figure 2. Instead, the slope decreases as the driving current increases, which is due to the effects from the rising temperature of the lasing region. Rollover occurs when the laser is no longer effective in converting additional current to laser light. Instead, the extra driving creates only heat. When the current is high enough, the strong localized heating of the laser region will cause the laser to fail.
Prime Lenses – In contrast, prime lenses only have one focal length. They are sometimes called ‘fixed’ lenses because the focal length is fixed at one distance between the lens and the image sensor to keep the subject in focus. You’ll know your lens is a prime lens because the focal length will be a single number listed in front of the millimeter measurement (e.g. 50 mm or 85 mm). Prime lenses have benefits over zoom lenses because they tend to be lighter weight and also have larger maximum apertures or f/stops. They’re popular in lower light and with portrait photography.
Quantum laserfor sale
As the temperature of the lasing region increases, more electrons are scattered, and a smaller fraction of them produce light instead of heat. Rising temperatures can also result in changes to the laser's energy levels that make it harder for electrons to emit photons. These processes work together to increase the temperature of the lasing region and to decrease the efficiency with which the laser converts current to laser light.
QuantumcascadelaserPDF
D-MountDesigned for OEM customers, our D-mount packages measure 12.0 mm long and have a 2.6 mm emission height. They provide high thermal conductivity and are offered in4.5 mm, 6.0 mm, or 7.5 mm sizes (measured by cavity length). Note that our DFB D-mount is 2.8 mm thick, whereas our FP D-mounts are 2.1 mm thick. Additionally, our D-mount packages are machined with two counterbored slots for mounting. The drive voltage and current are supplied via two large gold contact pads, which are suitable for wire bonding or probe connections. The lasers are electrically isolated from their D-mounts. A built-in thermistor provides real-time temperature measurements for control electronics.
Zoom Lenses – For zoom lenses, you’ll see both the minimum focal length and the maximum focal length that can be captured by the lens printed directly on your lens. 18-55 mm means that the minimum distance is 18 mm and the maximum distance between the lens and the image sensor is 55 mm. Zoom lenses have great utility because they capture all the focal lengths in between the range. You can carry less camera equipment but still, have a subject in focus at any of those distances.
Wide Angle Lenses (25 mm or less) – The first type of common lens with some of the shortest focal lengths are wide angle lenses. The industry standard for wide-angle lenses is to cover a focal length 25 mm or less on a crop sensor camera (40 mm or less on full-frame). It gives photographers the ability to capture a short focal length, but a wide field of view.
Two-Tab C-MountThe two-tab C-mount measures 6.4 mm x 4.3 mm x 7.9 mm (not including the tabs), provides high thermal conductivity, and can be secured using a 2-56 or M2 screw with the counterbored Ø2.4 mm (Ø0.09") through hole. The drive voltage and current are supplied through the tabs. As measured from the bottom of the C-mount, the emission height of the QCLs is either 7.15 mm or 7.39 mm depending on the chosen laser; the outer dimensions of the C-mounts are the same. All two-tab C-mount lasers sold on this page are electrically isolated from their C-mounts.
Hi my name is Brandon. I am an avid photographer and love the outdoors. ShutterTalk is where I share things that I have learned about photography and help other photographers, new or experienced, enjoy their cameras and taking pictures even more.
Quantum laserDARPA
The typical operating voltages of our QCLs and ICLs can be as high as 16 V and 8 V, respectively. These lasers do not have built-in monitor photodiodes and must be operated in constant current mode.
A pyroelectric camera (Spiricon Pyrocam IV) with 80 µm square pixels was scanned along the beam propagation direction, and the beam width was measured along the parallel and perpendicular directions using the second-order moment (D4σ) definition. Hyperbolas were fit to the beam width to extract M2 for each direction. The camera's internal chopper was triggered at 50 Hz since the pyroelectric effect is sensitive to changes in temperature rather than absolute temperature differences. A ZnSe window was present in front of the detector array to help minimize visible light contributions to the signal.
Every lens in your kit will have a focal length listed on the lens. Arguably, it’s the most important thing you need to know about your current lenses and it’s very important when buying new ones.
Minimize Physical HandlingAs any interaction with the package carries the risk of contamination and damage, any movement of the laser should be planned in advance and carefully carried out. It is important to avoid mechanical shocks. Dropping the laser package from any height can cause the unit to permanently fail.
We participate in the Amazon Services, LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliate sites.
Not to worry. While there are lots of numbers and letters on lenses, once you’re familiar with how to read them, it’s easy to know what lens you’re working with and what the lens will do for your photography. Rest assured, by the end of this guide you’ll be an expert on how to read camera lens numbers and choose the best lens for your next shoot.
Quantum lasertherapy
Normally Incident LightSince a plane of incidence cannot be defined for normally incident light, this approach cannot be used to unambiguously define perpendicular and parallel components of light. There is limited need to make the distinction, since under conditions of normal incidence the reflectivity is the same for all components of light.
Along with focal length and maximum aperture, you may find other numbers printed on your lens. Not all lens manufacturers have these numbers and letters printed, but it helps to be familiar with the other types of abbreviations you might find on a lens.
Avoid StaticSince these lasers are sensitive to electrostatic shock, they should always be handled using standard static avoidance practices.
In order to obtain the hyperbola coefficients a, b, and c for the parallel and perpendicular directions, we fit the discrete beam width measurements along each direction to hyperbolas, as shown in the graph to the right. These coefficients were substituted into Equation 2 (taking λ = 3.781 µm) to yield M2.
An electron must give up some of its energy to drop down to a lower energy level. When an electron descends one of the laser's energy steps, the electron loses energy in the form of a photon. But, the electron can also lose energy by giving it to the semiconductor material as heat, instead of emitting a photon.
When purchasing a wide-angle lens, you want to focus on getting as much speed for the most affordable price. Consider choosing a prime wide-angle lens as they have fewer components and tend to be priced cheaper. Prime lenses often times perform better at wide-angle focal lengths anyway as compared to their zoom counterparts.
Solder can be avoided entirely for two-tab C-mount and TO can lasers by using the LDMC20 or LDM90 laser mounts, respectively. If soldering to the tabs on a two-tab C-mount, solder with the C-mount already attached to a heat sink to avoid unnecessary heating of the laser chip. We do not recommend soldering lasers in TO can packages.
DFB QCLs at Custom WavelengthsFor distributed feedback (DFB) lasers, we can deliver a wide range of center wavelengths with user-defined wavelength precision. Our semiconductor specialists will take your application requirements into account when discussing the options with you.
Along with focal length, you will also find maximum aperture printed on your camera lens. Aperture refers to the size of the opening where light passes through to the sensor. It’s commonly written with f/stop on the camera lens (e.g. f/5.6, f/2.8, f/2). While there’s good information online on how to interpret f-numbers (it’s actually a ratio), what’s important for beginners to know is the lower the number, the larger the aperture or size of the space where light can enter. The higher the number, the smaller the aperture or opening and the less exposure.
Just like other telephoto lenses, ultra-telephoto lens buyers should shop for the most speed for the greatest focal length. Given how important it is to stop motion in these photos (and the high potential for noise and blur at long distances), it’s often better to choose a slightly shorter focal length if it means you can achieve a higher speed. Budgets for ultra-telephoto lenses vary greatly, but it is possible for a beginner to shop around for an affordable product that will shoot like the pros.
Quantum lasermilitary
Some of Thorlabs' DFB quantum and interband cascade lasers are uniquely suited for gas sensing and analysis. Select high heat load QCLs are designed to emit at wavelengths ideal for many gases commonly studied in spectroscopy (see the Spectroscopy tab for more information). These DFB quantum cascade lasers are guaranteed to reach their specified wavelengths within their tuning range and are single wavelength, allowing them to be tuned to specific gas spectra. Thorlabs also sells the ID3250HHLH interband cascade laser and the QD8050CM1 quantum cascade laser, which can be used for methane sensing. A list of these QCLs can be found in the Spectroscopy tab above, and more information is available by clicking on the blue info icons () next to the relevant Item #s below.
For this system, we obtained M2 = 1.2 ± 0.08 in the parallel direction and M2 = 1.3 ± 0.2 in the perpendicular direction. While this is just one example, we believe these results to be representative of well-collimated mid-IR lasers manufactured by Thorlabs, as corroborated by supplementary measurements we have performed in-house.
The graphs below and photos to the right illustrate some of our custom capabilities. Please visit our semiconductor manufacturing capabilities presentation to learn more.
Labels and symbols applied to the perpendicular and parallel components can make it difficult to determine which is which. The table identifies, for a variety of different sets, which label refers to the perpendicular component and which to the parallel.
A few lenses everyone should consider having in their camera bag: A 50 mm f/1.8 prime lens. It’s a gold standard for portraits and street photography. A versatile zoom lens with a range of at least 70-300 mm is also helpful to have around. It will give a bit more zoom than your standard kit lens and offer higher quality images. Finally, consider a wide-angle lens. It’s great for small quarters and shooting large objects like buildings. They don’t often come in basic lens kits but should be one of the first you consider adding on.
A pair of Infrared LED modules for use with custom night photography projects and NoIR-type camera modules!These modules emit 850nm infrared light allowing ...
The typical operating voltages of our QCLs are 7 - 16 V, while the typical operating voltages of our ICL is 5 V to 8 V. To get L-I-V and spectral measurements of a specific, serial-numbered device, click "Choose Item" next to the part number below, then click on the Docs Icon next to the serial number of the device.
Avoid Dust and Other ParticulatesUnlike TO can and butterfly packages, the laser chip of a C-mount or D-mount laser is exposed to air; hence, there is no protection for the delicate laser chip. Contamination of the laser facets must be avoided. Do not blow on the laser or expose it to smoke, dust, oils, or adhesive films. The laser facet is particularly sensitive to dust accumulation. During standard operation, dust can burn onto this facet, which will lead to premature degradation of the laser. If operating a C-mount or D-mount laser for long periods of time outside a cleanroom, it should be sealed in a container to prevent dust accumulation.