A laser system with low output power using a volume Bragg grating (VBG) of photothermal refractive glass and of high diffraction efficiency (0.994) as one of the end mirrors is demonstrated. The minute absorption of the VBG causes changes in various aspects of the laser performance including laser output power, shifting of laser wavelength, chirped grating period, and surface deformation of the VBG. Finite element analysis and T-matrix simulations indicate that the minute absorption of the VBG can induce changes in the thermal, mechanical, and optical properties, which are responsible for the phenomena observed in the experiments.
- Holographic gratings
- laser thermal factors