Investigation of high Bragg orders in ultrashort pulse written VBGs for applications in the blue spectral region

In recent years new applications for Volume-Bragg-Gratings (VBG) have moved the focus from the nIR spectral range to shorter wavelengths. Their unique narrow spectral reflectivity can for example be utilized for spectral filtering in quantum applications in the VIS or as feedback elements for stabilization of diode lasers in the blue spectral region [1]. The reduction of losses due to absorption plays a vital role in many of these applications. The key to achieving this is the tailored choice of material. Using ultrashort pulse laser processing offers the opportunity to realize VBG in fused silica, which is uniquely qualified due to its extremely low intrinsic absorption and large transparency window reaching well into the UV.