Rofin Liquid Light Guides

For UV - Visible - near IR

A liquid light guide is a single core transmitter of high intensity light. Various core materials are available to suit the UV, Visible and IR spectral ranges. Liquid Light Guides have a greater transmission of high intensity light than glass fibre optic bundles.

* High efficiency in 3 wavelength ranges - UV, visible, and near IR
* More efficient than glass fibre guides in the Visible range - up to 90% in a 2m guide
* Robust mechanical design with no problems of dim, patchy light associated with fibre breakage
* Wide variety of diameters, lengths available including custom designs
* Better UV transmission than quartz fibre guides at a fraction of the cost
* Cooler light than glass fibre guides - visible guides transmit minimal IR
* Liquid light core eliminates packing losses and provides totally uniform transmission with high Numerical Aperture (NA)
* Competitive pricing makes LLGs the most cost effective option


Liquid light guides are constructed with a flexible outer sheath containing a light conducting liquid core. The guide is sealed with high quality quartz windows and can be made transparent to all wavelengths from 230 nm (UV) to 980nm.

The guides are produced in a wide range of core diameters and lengths and are available to standard or customer-specified geometry and performance.

Type Standard apertures (mm) NA Spectral Range (nm) Applications
UV 3, 5, 8, 10 NA = 0.59 2a = 73infinity 275 - 700 Curing of inks, adhesives, coatings • fluorescence inspection • arc and tungsten halogen light sources • spectroscopy • solar
Visible 3, 5, 8, 10 NA = 0.59 2a = 73infinity 300 - 980 Medical / industrial endoscopy • illumination for photography, microscopy • arc and tungsten halogen light sources • spectroscopy

Bifurcated Liquid Light Guides

For dual source applications, we offer bifurcated liquid light guides (see diagram). Each leg has an active core of 3 mm and a length of 1, 1.5 and 2 meters (39, 59 and 79 inches).

Fibre-optic bundles vs Liquid Light Guides

* Liquid Light Guides offer higher transmission, particularly in the UV - typical 1m glass or fused-silica fibre-optic bundles transmit only 40% to 60% of incident light, mostly due to packing losses - in contrast, liquid light guides transmit 70% to 90%.
* Fused-silica fibre in particular is easily broken with even modest bending and twisting. Liquid light guides are rugged and our special sealing method, proven over many years use, ensures no leakage.
* High NA provides a large light acceptance angle. Typically, liquid light guide NA is around 0.5 whereas that of fused silica is 0.22 to 0.25.

Rofin is continuously improving its Liquid Light Guide range and so specifications can change without notice.

Download a PDF Specification Sheet for Liquid Light Guides