Patent ID: 6108356
Filing Date: 2000-08-22
Classification: H01S

Abstract:
A laser providing a preselected frequency laser output comprising:a) a laser resonator having a laser resonator cavity formed between a first reflective surface and a second reflective surface said resonator having a resonator optical axis;b) a lasing medium located within said laser resonator cavity for generating a fundamental wavelength beam;c) an optical parametric oscillator (OPO) formed between said first reflective surface and a third reflective surface said optical parametric oscillator cavity having an oscillator optical axis which is in part separate from said resonator optical axis and which in part overlaps said resonator optical axis;d) a nonlinear crystal located within said OPO cavity along said oscillator optical axis and along said resonator optical axis in optical communication with said first and said third reflective surface;said nonlinear crystal oriented to convert said fundamental wavelength beam into a preselected output wavelength beam having a preselected longer wavelength than said fundamental beam;e) means to direct said fundamental wavelength beam into optical parametric oscillator cavity along said oscillator optical axis and across said nonlinear crystal to convert a portion of said fundamental wavelength beam to a preselected output wavelength beam having a longer wavelength than said fundamental beam;f) said first reflective surface reflective of fundamental wavelength beam and at least partially reflective of output wavelength beam;g) means to direct said fundamental and output beams from said first reflective surface back across said nonlinear crystal to form additional output wavelength beam;h) a beam separator to separate said output wavelength beam from said fundamental wavelength beam;i) fundamental beam directing means to direct said separated fundamental beam back across said lasing medium for further amplification;j) output beam directing means for directing said separated output wavelength beam to said third reflective surface where said beam is at least partially reflected across said nonlinear crystal;k) an output coupler to direct a portion of said output wavelength beam outside said oscillator cavity.