A low-loss PLD fabricated garnet planar waveguide laser

Planar waveguide lasers have attracted increased attention in the recent years, particularly with a view to developing high average power diode-pumped solid state lasers. For diode-pumped schemes, the planar waveguide design can address requirements for optimal laser performance such as efficient coupling of the diode bar pump light into the guide due to both the excellent geometric match of the pump beam to the profile of waveguide facet as well as the possibility to confine non-diffraction limited beams by designing high numerical aperture structures, control of the spatial output of the waveguide by introducing design schemes such as double-cladding, large-mode-area waveguides, multimode interference as well as tapers and unstable resonators. The planar geometry is also ideal for efficient thermal handling and therefore, circumvention of problems such as thermal lensing, birefringence and fracture and in combination with a suitable fabrication technique, such structures can show with low propagation losses