Generation of UV laser light via intra-cavity frequency doubling of an AlGaInP-VECSEL

In recent years, vertical external cavity surface-emitting lasers (VECSELs) became an important category of power-scalable semiconductor lasers in a wide range of applications. Examples can be found in many fields of work as biophotonics, television or projectors, spectroscopy or lithography. Using external cavities and optical excitation, VECSELs exhibit high continuous-wave (cw) output power and near-diffraction-limited beam quality with a TEM00 Gaussian beam profile [1]. With an external cavity, the possibility of utilizing intra-cavity optical elements arise. Here, filters and frequency conversion crystals could be used intra-cavity to expand the spectral range of the laser by wavelength tuning or harmonic generation of coherent laser light.