Overview of Laser Line Tunable Filters and Tunable Laser Sources Applications

The Laser Line Tunable Filter (LLTF) is a non-dispersive, widely tunable bandpass optical filter. At its core lies a volume Bragg grating (VBG) which efficiently selects and filters all but a narrow spectral window from a broadband light source.

The LLTF provides a wider tunable range than other commercially available tunable filters. A single filter has the potential to offer full continuous tunability from 400 to 2500 nm, with an unrivalled out-of-band rejection of <-60 dB throughout this range. This instrument is the only commercially available tunable optical filter with an optical density higher than OD 5 over such a wide spectral range.

The LLTF can be combined with most commercially available broadband light sources such as Laser-driven Plasma Light Sources (LPLS) or a high repetition rate femtosecond lasers (Ti:Sapphire). One of the most popular combinations is the coupling of the LLTF with commercially available supercontinuum such as NKT Photonics’ SuperK series to create a Tunable Laser Source (TLS).