Liquid cooled solid state laser

Claim 1

A RADIATION PRODUCING DEVICE COMPRISING A SOLID STATE LASER ELEMENT IN WHICH STIMULATED EMISSION OF RADIATION OCCURS WHEN THE ELEMENT IS SUBJECTED TO PUMPING RADIATION, SAID ELEMENT EXTENDING ALONG A PREDETERMINED AXIS, REFLECTIVE MEANS AT THE ENDS OF SAID ELEMENT PROVIDING A RESONANT CAVITY EXTENDING AXIALLY OF SAID ELEMENT, AN ELONGATED CRYSTAL OF HIGH THERMAL CONDUCTIVITY MATERIAL HAVING A FIRST PORTION ENCLOSING SAID LASER ELEMENT AND IN THERMAL CONTACT THEREWITH THROUGHOUT THE LENGTH OF THE ELEMENT, SAID CRYSTAL BEING TRANSPARENT TO PUMPING RADIATION AND HAVING A SECOND PORTION EXTENDING FROM SAID FIRST PORTION LONGITUDINALLY OF SAID AXIS, COOLING MEANS CONTACTING SAID SECOND PORTION OF THE CRYSTAL AND RESTRICTED THERETO FOR MAINTAINING THE TEMPERATURE THEREOF WITHIN THE RANGE OF FROM ZERO TO ABOUT 100* K., AND A SOURCE OF PUMPING RADIATION ENCIRCLING SAID FIRST PORTION OF THE CRYSTAL, SAID LASER ELEMENT BEING EXPOSED THROUGHOUT ITS LENGTH TO PUMPING RADIATION FROM SAID SOURCE.