High-power quasi-CW diode-pumped 750-nm AlGaAs VECSEL emitting a peak power of 29.6 W and an average power of 8.5 W.

A peak output power of 29.6 W and an average output power of 8.5 W at a wavelength of 750 nm were demonstrated in quasi-CW multi-mode operation using an AlGaAs-based vertical external-cavity surface-emitting laser (VECSEL) diode-pumped at a wavelength of 675 nm.

Nonlinear absorption in lithium triborate frequency converters for high-power ultrafast lasers.

We report on an analysis of the nonlinear absorption in lithium triborate (LBO) used for second and third harmonic generation of ultrashort laser pulses at average powers in the order of kW and with sub-picosecond pulse duration. Thermographic imaging of the LBO crystals together with a simple analytical model revealed the presence of nonlinear absorption in both harmonic generation processes. Subsequent processing with a numerical model considering the nonlinear mixing, the absorption, and the heat conduction was used to estimate the absorption coefficients.