Intracavity Optics Control Laser Mode

Adaptive optics helped curb intracavity aberration in a diode-pumped Nd:YVO₄ laser's oscillation mode profile. Scientists at the University of Strathclyde in Glasgow, UK, incorporated the 37-element mirror directly into the Nd:YVO₄ laser cavity and developed a feedback control system to automatically compensate when thermal lensing altered the laser's transverse mode. The group described two optimization methods. One spatially filtered laser output through a pinhole and onto a photodiode to provide feedback, and the other assessed modal output collected from a CCD chip. The group described both techniques and the results in the July 1 issue of Optics Express.