Patent ID: 6061370
Filing Date: 2000-05-09
Classification: H01S,H05K

Abstract:
A laser for producing a fourth harmonic beam comprising;a) a first reflective surface and a second reflective surface to form an optical resonator cavity therebetween;said optical resonator cavity having an optical axis between said first and second reflective surfaces;b) a laser medium located within said cavity for generating a fundamental frequency beam of electromagnetic radiation (EMR) having a first preselected wavelength propagating from the front end and the back end of said laser medium;c) a second harmonic generator for converting a portion of said EMR of said first preselected fundamental frequency beam to a second harmonic beam in optical communication with said front end of said laser medium;d) said second harmonic generator including a second harmonic generation nonlinear crystal having a first EMR port for receiving and directing radiation through said crystal and a second EMR port for receiving and directing radiation through said crystal whereby radiation will enter said first EMR port, propagate through said crystal and exit said second EMR port and vise versa;e) means to direct said fundamental beam to said first EMR port;f) means to direct said fundamental beam propagating from said second ERM port to said second reflective surface and said second harmonic beam propagating from second EMR port to a second harmonic reflective surface so that said fundamental and said second harmonic beams are reflected to said second EMR port for propagation back through said second harmonic generator nonlinear crystal to produce additional second harmonic beam prior to any conversion of second harmonic beam to a higher harmonic beam;g) means to direct the EMR propagating from said first EMR port to a third harmonic generator;h) said third harmonic generator including a third harmonic generation nonlinear crystal having a third EMR port for receiving and directing radiation through said crystal and a fourth EMR port for receiving and directing radiation through said crystal whereby radiation will enter said third EMR port, propagate through said crystal and exit said fourth EMR port and vise versa whereby a portion of the fundamental and a portion of second harmonic beam are converted to a third harmonic beam;i) means to direct the EMR propagating from said fourth EMR port to a fourth harmonic generator;j) said fourth harmonic generator including a fourth harmonic generation nonlinear crystal having a fifth EMR port for receiving and directing radiation through said crystal and a sixth EMR port for receiving and directing radiation through said crystal whereby radiation will enter said fifth EMR port, propagate through said crystal and exit said sixth EMR port and vise versa whereby a portion of the fundamental and a portion of third harmonic beams are converted to a fourth harmonic beam;k) a fourth harmonic beam separator in optical communication with said sixth EMR port to separate said fourth harmonic beam from said fundamental beam;l) means to direct the separated fourth harmonic beam outside said optical resonator cavity;m) directing means to direct said fundamental beam back through said laser medium.