Glass bead laser amplifier with phase conjugate mirror

Abstract

A glass bead laser amplifier which is designed to operate efficiently at relatively high optical power outputs, and which is designed to be easily manufactured and scaled up in size to produce high power laser beams. The laser amplifier cavity if filled with doped glass lasing beads or elements which are packed therein to be in contiguous contact with each other. The shape of each glass element preferably provides a relatively large ratio of the external area to volume of the glass lasing element, to provide for efficient cooling thereof. A cooling system is provided for the laser amplifier cavity in which a coolant fluid circulates through the laser cavity around and between the contiguous glass lasing elements for cooling thereof. The cooling fluid is selected to have an index of refraction substantially matching that of the glass lasing elements to substantially reduce scattering of light passing through the glass/cooling fluid interfaces in the laser amplifier cavity. Moreover, a conjugate mirror is placed adjacent to one end of the laser amplifier cavity for reflecting the laser light which has passed once through the laser amplifier cavity back therethrough, to cancel the initial optical distortions introduced into the light beam as it initially passed through the laser amplifier cavity and the glass/cooling fluid interfaces therein. This results in the production of an output laser beam substantially unaffected by optical distortions which would otherwise be introduced by the laser amplifier.