These Liquid Light Guide Adapters allow the integration of our Ø3 mm and Ø5 mm liquid light guides into any of our selection of SM1-threaded (1.035"-40) components, such as fixed optic mounts, kinematic optic mounts, and lens tubes. The LLG is secured with a nylon-tipped setscrew using a 1/16" hex key (found in the CCHK kit).

Flexible fiber opticlightguide

Acree Technologies offers a complete range of DLC coatings, in all phase compositions. Based on your application, Acree will help you determine which DLC coating structure is best suited to your project.

All liquid light guide adapters come with a Ø3 mm LLG to SM1 (Ø1.035"-40) AD3LLG adapter preinstalled, making them compatible with Ø3 mm core liquid light guides out of the box. They are also shipped with a Ø5 mm LLG to SM1 (Ø1.035"-40) AD5LLG adapter, which can be swapped in by unthreading the AD3LLG and replacing it with the AD5LLG. This allows the adapters to connect with Ø5 mm core liquid light guides.

The bottom line is that DLC has been proved safe and effective for implanted medical devices such as stents, hip and knee joints. DLC coatings allow implants to maintain integrity, avoid formation of debris, prevent uncontrolled cell growth, and to not cause infections.

Different process parameters control the characteristics of DLC coatings. These include factors such as:  the deposition method, the ratio of sp2 to sp3 carbon, substrate bias voltage, process time, ion energy and density, and substrate temperature. Thus many attributes, such as coating thickness, hardness, resistivity, hydrogen content and others can be controlled as needed for various applications.

The optical end faces of these liquid light guides are made of fused silica, PTFE and either aluminum, chrome plated brass, or stainless steel. All of these materials are very resistant to all common cleaning solvents, making them easy to clean. Please note that when using solvents to clean the end faces, you cannot submerge the tip of the light guide in the solvent, or use a heavily soaked cleaning pad, as the solvent may get into the light guide, causing damage. If you find that debris from the light guide end cannot be removed by using a solvent, you can gently use a razor blade to clean the tip, making sure that you do not chip the edge of the fused silica glass window.

Lightguide design

All transmission data presented here is typical. The data was taken with a bend radius of 400 mm and the maximum variation from lot to lot is 5%. As a function of length, only minimal variations (<5%) are expected between our 4' (1.2 m), 6' (1.8 m), and 8' (2.4 m) long liquid light guides. The blue-shaded region in each graph denotes the spectral range over which we recommend using that liquid light guide.

Lightguide design guidelines

These adapters are calibrated such that the image plane from the LLG output is located at the back aperture of the objective when used with the compatible epi-illuminator module; to optimize illumination for your microscope or realign the image plane, the collimation can be fine-adjusted via the knurled ring on the thread adapter (see image to the bottom left).

DLC is an acronym for diamond-like carbon. DLC has some of the valuable properties of diamond, including:  high hardness, low friction, resistance to wear, chemical inertness, biological compatability, electrical insulation, optical transparency, and smoothness. In common terms, DLC is harder than natural diamond and slicker than “Teflon.”DLC coatings are used to impart some of the useful characteristics of diamonds onto other materials. DLC coatings can be deposited on nearly all metals, metal alloys, and also on nonmetals such as silicon, glass, ceramics, plastics, etc. DLC can be deposited at low (<200C) substrate temperature.DLC coating has many commercial applications, including machine tools, aerospace parts, engine parts, medical implants, and high-end watches. Depending on the application, different formulations of DLC coatings are used.

All of our LLGs are available with custom core diameters or custom lengths as made-to-order items by contacting Tech Support.

LightGuide Cable

Lightguide meaning

Carbon comes in several allotropes, each of which has its own unique structure. Two of these allotropes, diamond (sp3) and graphite (sp2), are found in DLC. Diamond (sp3) has carbon atoms arranged in 3 dimensional cubic lattices while graphite has a layered, planar structure in which the layers are arranged in a honeycomb lattice.  These two allotropes are the main ingredients of DLC, of which there are 7 different forms.

The SLSLLG1 is designed with an uncoated collimating lens, which provides a wide operating range from 185 nm - 2.1 µm. For superior performance from 350 nm - 700 nm, the SLSLLG2 and SLSLLG3 lenses use an AR-coated lens that provides improved coupling efficiency in this wavelength range. Additionally, the SLSLLG2 features an integrated diaphragm shutter and an external controller that can operate at continuous frequencies up to 10 Hz and burst frequencies up to 15 Hz. For more information on the integrated shutter, please refer to the manual.

These light guides can be mounted to an optical breadboard by using one of our VH1(/M) V-Mounts, a Ø1/2" (12.7 mm) post, and post holder. They can also be mounted to SM1-threaded (1.035"-40) components, SM2-threaded (2.035"-40) components, or microscope ports using the adapters sold below. Thorlabs also offers collimating and coupling adapters for the liquid light guides, which are sold separately below. The SLSLLGx coupling/collimating adapters feature external SM2 (2.035"-40) threading on the housing that makes them directly compatible with our benchtop light sources. Additionally, we offer a variety of collimating adapters that allow the LLGs to be coupled to a Cerna® microscope or the illumination ports used by various microscope manufacturers.

LightGuide Optics

These liquid light guides are offered from stock with a core diameter of either 3 or 5 mm, and in lengths of 4' (1.2 m), 6' (1.8 m), or 8' (2.4 m). LLG3-4T and LLG5-4T light guides can have either end used as an input. LLG3-4Z and LLG5-4Z liquid light guides have a yellow band that indicates the end that must be used as the input because it contains a filter to protect the light guide from radiation below 420 nm. Light guides with a 340 - 800 nm wavelength range each have a yellow band that acts as a visual indicator for use with our previous-generation HPLS343 (for Ø3 mm core) or HPLS345 (for Ø5 mm core) high-power plasma light sources; the LLG is correctly inserted when the edge of the band is flush with the front panel of the instrument.

Despite the name “diamond-like,” DLC is not in fact like  natural diamond. DLC coatings do not have the crystalline geometries that are found in nature, but instead are amorphous. DLC coatings are made from random alternations between cubic and hexagonal lattices, which creates no long-range order and therefore no fracture planes along which to break. The result is an exceptionally hard material. DLC looks smooth when seen with visible light, but under a microscope it actually resembles a cobblestone street.

These adapters quickly mount onto the end of either the Ø3 mm or Ø5 mm Liquid Light Guide (LLG). The LLG is secured into the back of the collimator via a 4-40 setscrew with a 0.050" hex.

Thorlabs offers collimation adapters with AR-coated aspheric condenser lenses (EFL = 40 mm) for collimating the output from our light sources. Four different collimator housings are available; each is designed to mate to the illumination port on an Olympus IX/BX, Leica DMI, Zeiss Axioskop, or Nikon Eclipse Ti microscope.

LEDlightguide panel

DLC coatings creater lower coefficients of friction. As friction is the enemy of almost all moving parts, lowering it creates nearly universal improvement, regardless of the industry. Thus, DLC is found in engines, tools, machining of cast and wrought aluminum, plastic injection molds, pumps, machine parts, bearings, cams, and even razor blades. Reduced friction also reduces the need for lubrication, which improves efficiency within the supply chain from raw material through to the end user.

Thorlabs offers collimation adapters to couple Ø3 mm or Ø5 mm liquid light guides (LLGs) to our CSE2100 and CSE2200 Cerna Epi-Illuminator Modules; see the table at the bottom right for compatibility information. For even illumination at the back focal plane of the objective, these adapters feature an optic pair of an achromatic doublet and a double convex lens.

Thorlabs' Liquid Light Guides (LLGs) offer high transmission from 220 - 650 nm, 340 - 800 nm, or 420 - 2000 nm (see the Graphs tab for typical performance). These LLGs can be used with our SLS201L(/M) compact quartz tungsten-halogen (QTH) light source, SLS301 and SLS302 benchtop QTH light sources, SLS401 and SLS402 benchtop xenon arc light sources, or SLS204 deuterium UV light source. For large core diameters, liquid light guides are a more efficient transmission solution than fiber bundles as they eliminate the packing fraction loss (dead space) that fiber bundles have.

These adapters utilize a male D3T dovetail adapter to connect to the end of the epi-illuminator module; for additional information about microscope dovetails, see the full web presentation. The LLG is secured via a thumbscrew at the back of the adapter.

DLC coating is an amorphous, stable carbon layer that does not react to acids or alkaline. It is highly resistant against oxidation and corrosion. The high density and amorphous structure of DLC inhibit corrosive by-products from penetrating into tools. The chemically inert characteristics of diamond-like coatings dramatically reduce possibility of cold welding and material pickup on the surface of the tool.

DLC has been tested extensively for biocompatibility. Studies (both in vitro and in vivo)have focused on the interaction between DLC and macrophage cells (large white blood cells that engulf foreign bodies), fibroblasts (connective tissue forming cells) and osteoblasts (bone-forming cells).

Ledlight guides

DLC is a popular decorative coating on fine watches. When used on a watch, DLC coatings provide superior durability and wear resistance. The coatings, which are shiny and black, also create aesthetic appeal. Glancing blows against a hard surface, which may dig in and damage a normally coated watch, are far less likely to mar a DLC coated case. These characteristics, along with the beauty of DLC, have helped it to grow in popularity as a hard surface coating for high-end watches.

DLC’s hardness also makes it durable. DLC coating protects moving parts from abrasion maintaining smooth movement much longer than uncoated parts. Engines with DLC coated parts create more horsepower, and have longer lifetimes from mechanical parts that rotate, slide, and face other types of wear. For example, DLC is now standard practice on camshafts in all types of Formula 1 racing including cars, motorcycles, and boats.

DLC coatings produce dramatic improvement in performance and life of tools, components, and machines. The hardness of DLC coatings is the foundation for their benefits. DLC in all forms is extremely hard. Depending on which form is applied, DLC is as hard, or even harder, than natural diamond. In ta-C form, DLC typically measures between 5000-9000HV. Other forms range from 1000-4000HV.The high hardness of DLC coatings reduces the likelihood of hard particle penetration into tools or parts. Optimized DLC coatings have been shown to improve the lifespan of tools by up to a factor of 10. For example, DLC coatings created major improvements harsh environment of machining stainless steel. Prior to DLC coatings, jobs were done with uncoated tools and hard to work at low speeds and feeds. DLC was a massive game changer, improving process speeds and tool longevity by an order of magnitude. Because of its durability, DLC is used as tribological coating for machine tools such as drill bits, saws, and dies.

DLC, in its early development, had problems with adhesion. DLC tends to have high flim stresses, which when combined with lattice mismatches between DLC and many substrates, led to poor adhesion. However, this problem was solved by the use of multilayer coating “stacks” that include an adhesion layer.  These stacks reduce Hertzian stress concentrations near the coating/substrate interface by virture of graded interfaces, which create a higher modulus of elasticity. This ensures that there are no abrupt changes in composition, and that the stress is introduced into the coating gradually, resulting in excellent adhesion of the DLC. Today, all DLC coatings are stacked, and this influences other important coating properties besides adhesion. The multilayer structures act as buffers, which reduce film stresses. This allows for thicker coatings, which creates excellent properties, such as: extremely high microhardness, low coefficients of friction, slower rates of wear, etc. A commonly used stack is: titanium, titanium nitride, titanium carbonitride, titanium carbide, and finally, DLC.

DLC comes in 7 forms, of which “tetrahedral amorphous carbon (ta-C)” is be considered to be the “pure” form, since it consists only of sp3 bonded carbon atoms. However, due to patent restrictions and expensive licensing fees, pure ta-C is typically reserved for high value components. The other 6 forms of DLC, which include mixtures of sp2 and sp3 carbon along with other elements, are therefore more economical and more commonly applied.

These Liquid Light Guide Adapters allow the integration of our Ø3 mm and Ø5 mm liquid light guides into any of our selection of SM2-threaded (2.035"-40) components, in particular our SLS301, SLS401, and SLS402 broadband light sources. The adapter can be directly threading onto a light source without the need to adjust the position of the collimating lens.