High brightness, sub-nanosecond, and compact passively Q-switched laser with intracavity volume Bragg gratings

摘要

A high brightness, high energy passively Q-switched (PQS) Nd:YAG laser is presented using volume transmitting Bragg gratings (TBGs) as angular filters. A planar cavity with a length of 1 cm, an 800 μm diameter pump beam, a 20% transmission Cr:YAG saturable absorber, and a 40% output coupling resulted in output pulse energies greater than 1 mJ and durations near 600 ps. In order to increase brightness without altering cavity length, a TBG with narrow angular selectivity placed in the cavity to suppress the higher order transverse modes allowing for near diffraction limited output.