Abstract

Photonic crystals (PhCs) fabricated in the bulk of dielectric media have already been demonstrated to show a low-pass spatial (angular) filter functionality. [1] These PhC filters are fabricated in inorganic glasses through a femtosecond laser writing process. The most promising aspect of such filters is their direct integration into the cavities of laser micro-resonators. In particular, the integration of such filters in microchip lasers as demonstrated recently [2], where the brightness of emitted radiation as well as its spatial quality was strongly increased. The maximum available divergence depends on the PhC angular range of filtering. Therefore it is very important to optimize the structure of the filtering PhC to obtain optimum filtering.

© 2017 IEEE