Role of optical resonator on the pointing stability of copper vapor laser beam

摘要

This paper presents a first comprehensive study on the pointing stability of copper vapor laser with an emphasis on bringing out the role of optical resonator. Long term (approx10 min), single pulse, far-field beam pointing stability of a 5.5 kHz repetition rate copper vapor laser (lambda velence 510 nm) with plane-plane, unstable and filtering resonators, is studied. It is established that the resonator optics largely decides the CVL pointing stability. Minimum beam pointing angle of 8 (mu)rad from generalized diffraction filtered resonator (GDFR) is obtained in contrast to a maximum value of 120 (mu)rad from the plane-plane resonator. The unstable resonators data is in between. The relative trends in CVL pointing stability are discussed in terms of wave-front distortions due to resonator mode build up from optical noise, thermal and mirror misalignment effects. The degree of optical resonator immunity to phase distortions dictates the net pointing stability achieved.