Another consideration is germanium’s density. At 5.33g/cm3 it does not float like a butterfly and sting like a bee. It’s heavy. Quite heavy and this will need to be considered when designing weight-sensitive systems.

Microscopeparts

Reviewed & updated 06/16/2017. Creation of this web page was originally supported as part of the Southwest Environmental Health Sciences Center at the University of Arizona, NIEHS P30 ES006694.

One of the more common applications we see at Firebird Optics for germanium windows is in low power CO2 laser systems. With a Laser Induced Damage Threshold (LIDT) of 10 J/cm2, germanium windows are not suited for high power or continuous wave (CW) lasers. Part of the reason for this is higher powered lasers cause temperature increases, dramatically dropping transmission properties over 100ºC and eventually damaging the substrate itself once temperatures near 600ºC are reached.

Various BBAR coatings typically requested are 3-5µm, 3-12µm, 2-14µm and 8-12µm though we can do even more customization. You can fill out our custom request form and see what Firebird Optics can do for your application.

If high transmission is the only consideration, you’d be best served to double coat your windows with BBAR over particular wavelength ranges and you can see transmissions all the way up to 99%. Now we’re talking!

Ocular Lens (or eyepiece). Focuses the image from the objective into your eye. · Eyepiece Tube. Connects the eyepiece with the objective lens. · Objective Lenses.

Objective lensmagnification

One cautionary detail to note is that your germanium window will not appreciate being exposed to high temperatures. In fact, there is an inverse relationship to temperature and transmission when it comes to this material. As your temperature goes up, the transmission properties will drop precipitously, a property known as thermal runaway. Anything over 100ºC is not recommended. By the time it reaches 200ºC it is nearly opaque at all wavelengths. If you need a high temperature window, you’re better suited to stick with a material like MgF2, YAG or our old friend sapphire.

Typesof objectivelenses

One very common scenario we see germanium utilized is inside high and low speed wind tunnels for jet propulsion studies. Typically, these windows are much larger than stock configurations reaching sizes in excess of 190-200mm.

In fact, at an eye-popping Knoop Hardness of 2000kg/mm2, one might wonder, why wouldn’t I just use sapphire windows instead of germanium? While sapphire is the undisputed champion of robust optics in the UV/VIS and mid-IR with a wavelength range that dips into the far UV range at 150nm, it can only be used up to 4.5µm. This leaves germanium as the best and only choice for brutally tough IR applications. This is typically why you will see germanium windows and lenses serving in places as inhospitable as outer space, battlefields and in the middle of high-powered CO2 laser systems. More on this later.

The resolution of a microscope objective is defined as the smallest distance between two points on a specimen that can still be distinguished as two separate ...

You definitely don’t want to breathe in germanium dust so care must be taken while handling these optics. Using gloves whenever possible and washing hands should be part of any standard operating procedure.

On the other hand, an AR-coated germanium will feel right at home in a low power pulsed laser setup. One particularly noteworthy application is in quantum cascade lasers (QC), which is used in high-end materials science. Quantum cascades are used by such institutions as the Max Planck Institute of Quantum Optics in Garching to produce ribbons and strip structures as well as to produce new materials for use in medical applications. Pretty cool stuff!

Alternatively, you can use liquid CO2 from a specialized nozzle for cleaning though this requires additional cost in terms of equipment. While you will get a better, more controlled cleaning and can be used for stubborn stains, care must be taken to work in a controlled moisture-free environment and we do not recommend this for typical end-users.

An uncoated germanium window is a decent IR generalist but specific optical coatings can really kick things up a notch. Diamond-Like Carbon (DLC) coatings can make this already hard material even more resistance to severe abrasions, environmental damage, mechanical strikes, thermal shock and whole other host of adversities.

Whatarethe3objectivelenses ona microscope

Light microscopes can, under the best conditions, resolve objects that are approximately equal to half the size of the wavelength used. In the real world this comes out to objects that are 250-300nm in size, if you are using a NA=1.4 objective lens (under optimal conditions). This means that you can make out two adjacent objects in this size range, assuming that you can see at least a 25% dip in intensity between them (Rayleigh criterion). Sample preparation is especially important when you want to resolve structures this small.

Aug 23, 2024 — A linear motor stage is a high speed linear stage design of a motorized linear stage that provides high-precision positioning. The drive train ...

Germanium makes a good electromagnetic interference (EMI) shielding material and can shield IR systems on planes from other nearby signals that would render the system ineffective. This effectively creates an IR Faraday cage or as we like to refer to it, an aerospace tin foil hat. Typical resistance for EMI-grade germanium is approximately 4 Ohm per cm but this depends on the required level of spurious signal suppression. A germanium window made to these specs can effectively short out any errant signals and keep the IR system running well.

When not in use, we recommend storing your germanium windows wrapped in lens tissue with humidity below 30% and between 15 and 25ºC. While germanium is pretty tough stuff, these are the ideal conditions that will prolong the life of your window.

Shop high-quality magnifiers, loupes, and magnifying glasses at Magnifier.com. Affordable prices, expert-rated lenses, and USA-made options.

Objective lensfunction

We respectfully acknowledge the University of Arizona is on the land and territories of Indigenous peoples. Today, Arizona is home to 22 federally recognized tribes, with Tucson being home to the O’odham and the Yaqui. Committed to diversity and inclusion, the University strives to build sustainable relationships with sovereign Native Nations and Indigenous communities through education offerings, partnerships, and community service.

The “cost” of obtaining a higher NA is that the working distance (WD) of the lens becomes much shorter. Working distance is “… the distance between the objective front lens and the top of the cover glass when the specimen is in focus. In most instances, the working distance of an objective decreases as magnification increases.” (1) A smaller working distance can be a problem when you cannot see an object with a high magnification lens, even though you could see it with a low magnification lens. A 10x objective can have a WD of several millimeters (4-10mm, or 4000-10,000um). A well corrected, high NA 20x dry objective will have a WD of slightly less than 1mm (1000um). Most well corrected, high NA 40x and 60x oil objectives have working distances on the order of 0.1mm (100um).

get wrecked! damage done to germanium windows by high power lasers. source: http://www.mdpi.com/2076-3417/10/10/3578/htm

Germanium holds the high ground when it comes to transmission range getting that additional coverage from 7-16µm, which silicon lacks. On top of this, germanium has higher electrical conductivity making it a more suitable candidate as an optical component in laser systems.

Many of us have looked though the eyepiece of a department store microscope and seen a fuzzy looking “something” with the highest magnification objective lens. It’s not completely surprising that an inexpensive lens would give a blurry image. There are many optical aberrations that need to be corrected to manufacture the expensive lenses that are used on research grade microscopes.

MSE PRO™ Ball Lenses MSE supplies offers Ball Lenses made of N-BK7/H-K9L, Sapphire and Fused silica with diameter between 0.5mm to 50mm. Ball lenses are a ...

Now for some fun stuff. We hear from plenty of our customers where their germanium windows are seeing action. Here are some highlights:

Ocularlens microscope

The best way to clean the windows is to use either ethanol, isopropyl alcohol, methanol, reagent-grade acetone or lint-free lens cloths. You can also use nitric acid but this material, while okay for germanium can corrode other optics or mounts that may be nearby in your system.

Germanium windows are optical windows that are completely impermeable to UV and VIS light giving them a dark, metallic appearance to the naked eye. However, when it comes to the IR range this is where germanium truly shines with an excellent, broad transmission range from 2-16μm making it an ideal candidate for Mid-Wave-IR (MWIR) and Long-Wave IR (LWIR) applications. The sharp transmission cut-off before 2µm also enables germanium to be used as a long pass filter, only transmitting wavelengths in excess of 2µm and fully blocking everything before it.

What does thestagedoona microscope

One common application for germanium is in night vision goggles. For these types of applications, both the inside and outside surfaces of the germanium is polished to a mirror finish and coated with multi-layered thin film filters to reduce any reflection of IR light. This enables optimal IR transmission essential to night vision/thermal imaging. As these windows will have excellent sensitivity at long range, this enables warfighters to retain long stand-off distances increasing safety and mission-effectiveness. Germanium is a literal life-saver.

Firebird Optics manufactures these types of windows in various geometries, coatings and can also produce lenses, prisms and various other optical components from germanium. Now back to your regularly scheduled programming…

Silicon (Si) is germanium’s next door neighbor who frequently borrows sugar. Both have an atomic number of 14, absorb visible light and have sharp cut-offs making them also function as long pass filters. In addition, there is similarity with their transmission ranges with silicon transmitting from 1.2-7µm. However, this is where they begin diverging. Silicon is far lighter with a density of 2.33g/cm3, making it ideal for weight-sensitive applications and less than half the density of germanium. Moreover, it is more thermally resistant than germanium and with a Knoop Hardness of 1150 it is also harder and less brittle. Silicon also costs less making it a better candidate in several applications.

Launch the Support Package Installer from your version of MATLAB and navigate to the correct support package. ... Option 2: "Get Support Package" Button (.

Since germanium windows have a high index of refraction of approximately 4.0 in the range of 2-16μm, transmission with minimal refraction is guaranteed but without any additional coatings only around 50% of the beam is able to pass through. Those are rookie numbers and in most applications we’ll need to boost our window signals via various coatings. While this may be a disadvantage for optical windows this property comes in handy for novel lens designs and ATR optics where refraction is desired.

The UArizona Microscopy Alliance is a volunteer and collaborative effort to bring information about shared microscopy facilities to the University of Arizona and the community.

High refractive index enables excellent performance for lenses, ATR optics or beamsplitters. For optical windows, AR coatings can be added to boost performance.

Frequently, DLC coatings are often paired with Broadband AR Coatings (BBAR) to not only up the mechanical performance but also the transmission properties. Typically, a window is coated on one side with DLC and the other side with BBAR (typically in the 7-14μm range to boost both of these properties in tandem. This combination can increase the transmission to well over 85% in the target wavelength range. Optical windows treated in this manner will pass a variety of tests including MIL-C-675-C, MIL-STD-810 and APCM-01071.00001 and can survive salt water, humidity, high and low temperatures and hard smacks.

High magnification without high NA does not give the resolving power that most people expect from a research grade microscope.  Using a high NA objective lens means that you are most likely sacrificing working distance (how deep into the sample that you can focus) for higher optical resolution. In most instances this is a very acceptable trade off.

A volunteer and collaborative effort to bring information about shared microscopy facilities to the University of Arizona and the community.

SID4 SWIR is a cost-effective wavefront sensor with high resolution and high sensitivity.Accurate wavefront analysis in SWIR source and lens testing.

6 — Wolf Hall: The Mirror and the Light review – six hours of utter TV magic. The final instalment of Hilary Mantel's masterpiece is the most ...

We’ve already explored why you would pick germanium over sapphire but why would you pick germanium over silicon or vice versa?

Numerical Aperture (NA) is “… a critical value that indicates the light acceptance angle, which in turn determines the light gathering power, the resolving power, and depth of field of the objective.”(1) As light passes through a sample, the information describing the highest resolution information in the sample is diffracted at a very wide angle. Low magnification lenses typically have low NAs, meaning that they cannot capture the highest resolution information. To capture the widely diffracted information, high NA lenses move the front of the lens closer to the sample (increases the light acceptance angle). Dry lenses can only have NAs of up to 1.0. By using specially formulated oil and oil lenses, NAs of up to 1.4 can be achieved.

Whatisobjective lensinmicroscope

One microscope has one to four objective lenses, some of which are forward-facing and others rear-facing. The magnification power of each lens varies. Nose ...

As you’d imagine, since germanium tags along with warfighters, it needs to be durable in all adverse conditions from desert, sea, high altitude, etc. The DLC coatings can take a serious beating with temperatures ranging from -80ºF to 160ºF, 24 hours of continuous sea spray, ocean immersion for over 24 hours and being immersed in a sandstorm. Additionally, the coatings can withstand heavy mechanical damage and chemical attacks.

Purpose:The divergence calculator uses the LiveMath plugin to calculate the divergence of a vector field. Restrictions on Use: This plug-in does not load ...

Germanium (Ge) is a shiny, hard element with a Knoop Hardness of 780kg/mm2 making it, along with its far stronger sister sapphire, the default candidate for applications where the environment is likely to put a beating on the material. For a full breakdown of how to wade through all of the major optical window choices check our optical window guide.

Germanium ends up in some interesting places including defense aircraft navigation, reconnaissance and surveillance systems soaring in the stratosphere on an airplane or even as part of a satellite.