Bundesministerium für Bildung und Forschung
Stabilized diode lasers around 40 nm using ultrashort-pulse-written volume Bragg gratings in silica glass.
𝗠𝗼𝘁𝗶𝘃𝗮𝘁𝗶𝗼𝗻
In fluorescence microscopy, laser diodes with different wavelengths, including in the visible range, are used to excite different dyes. In order to do this efficiently and accurately, it is important that the wavelength ranges of the laser diode are narrow and stable.
In order to minimize the change in the wavelength of laser diodes at different powers or due to fluctuating ambient conditions, a reflector that only works for a narrow wavelength range is placed in front of the laser diode. The laser diode wavelength adjusts to this – it is stabilized. For the wavelength range around 400 nm, however, conventional reflectors absorb part of the radiation, resulting in power and wavelength fluctuations and a shorter service life of the product.
Aims and procedure
In the VBG4Diode project, LASOS Lasertechnik GmbH and Friedrich Schiller University Jena have joined forces to develop new types of reflectors in order to realize stabilized diode laser systems at 400 nm. The reflectors consist of a glass block modified in the micrometer range and are so-called volume Bragg gratings (VBG). Special glasses are needed for the current manufacturing process. In this project, a new process is to be developed to realize VBG directly in silica glass, which has a significantly lower absorption in the 400 nm wavelength range.
Innovation and Perspectives
With the development of temporally and wavelength-stable laser diodes for the 400 nm wavelength range, more precise, more efficient and longer-lasting light sources can be made available for use in biophotonics, such as fluorescence microscopy.
