Liquid Light Guides
Close-Up of Liquid Light Guide End
- Excellent Transmission from 340 to 800 nm
- Numerical Aperture of 72°
- Suitable for Rugged Environments
- Adapters Designed to Mate Ø3 mm or Ø5 mm Liquid Light Guides to SM1 Thread Standard Available Below
- Microscope Collimation Adapters Available Below
- Ø2 and Ø8 mm Cores Available Upon Request
Thorlabs' Liquid Light Guides (LLGs) offer outstanding transmission from 340 - 800 nm for white light illumination applications. 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 light guides are recommended for use with tungsten halogen, xenon, or metal halide light sources and can be mounted to an optical breadboard by using one of our VH1 V-Mounts, a Ø1/2" (12.7 mm) post, and post holder. The Ø3 mm and Ø5 mm light guides can also be mounted to SM1-threaded (1.035"-40) components using the adapters sold below.
These liquid light guides are offered from stock in lengths of 4', 6', and 8' with a core diameter of either 3 or 5 mm, and their long-term temperature range is -5 to 35 °C. LLGs with custom lengths or core diameters of 2 or 8 mm are also available as made-to-order items by contacting Technical Support.
Thorlabs also offers microscope collimation adapters for the Ø3 mm and Ø5 mm liquid light guides. These adapters allow the LLGs to be directed into the illumination ports used by various microscope manufacturers. For more information, please see below.
All transmission data presented here is typical. 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 shaded regions in the graphs below denote the spectral range over which we recommend using these liquid light guides.
Upon request, we can provide liquid light guides with Ø2 mm or Ø8 mm core sizes made from the same material as our Ø3 mm core and Ø5 mm core options. Typical transmission curves for these are provided below as a reference. For more information, please contact Technical Support.
Liquid Light Guide Dimensions
|Active Core Diameter||Standard End Fittings||Protective Sleeve||Min. Bending Radius|
|2 mma||4 +0/-0.1 mm||6.7 ± 0.1 mm||8 ± 0.1 mm||20 ± 0.1 mm||5.5 ± 0.1 mm||30 mm|
|3 mm||5 +0/-0.1 mm||20 ± 0.1 mm||9 ± 0.1 mm||24 ± 0.1 mm||7 ± 0.1 mm||40 mm|
|5 mm||7 +0/-0.1 mm||20 ± 0.1 mm||10 ± 0.1 mm||24 ± 0.1 mm||9.5 ± 0.1 mm||60 mm|
|8 mma||10 +0/-0.1 mm||20 ± 0.1 mm||15 ± 0.1 mm||40 ± 0.1 mm||12.5 ± 0.1 mm||100 mm|
The drawing and photograph below illustrate the dimensions given in the table above. 180 ± 0° indicates the flatness tolerence between the metal and black material in the segment labled I2.
Cleaning the Optical End Faces
of Liquid Light Guides
The optical end faces of these liquid light guides are made of fused silica, Teflon 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.