A resonant waveguide grating composed of a single high-index layer and a sub-wavelength structure was used to select the polarization and the spectral linewidth of an Yb:YAG thin-disk laser. In fundamental mode (M² ≈ 1.1) up to 70 W with a spectral linewidth of 20 pm (FWHM) were extracted whereas in multimode operation (M² ≈ 6) up to 123 W of output power with a spectral line width of 0.5 nm (4 times lower as compared to the operation with a standard HR mirror) were achieved. The degree of linear polarization (DOLP) exceeded 99% in both fundamental and multimode operation.
- M. Vogel, M. Rumpel, B. Weichelt, M. Haefner, C. Pruss, A. Voss, W. Osten, M. Abdou Ahmed, and Th. Graf, “Single-layer resonant-waveguide grating for polarization and wavelength selection in Yb:YAG thin-disk lasers,” Opt- Exp. 20, 4024-4031 (2012).
Contact person: Dr. Marwan Abdou Ahmed