Abstract: A novel method and apparatus for suppressing ASE and parasitic oscillation modes in a high average power laser is introduced. By roughening one or more peripheral edges of a solid-state crystal or ceramic laser gain media and by bonding such edges using a substantially high index bonding elastomer or epoxy to a predetermined electromagnetic absorbing arranged adjacent to the entire outer surface of the peripheral edges of the roughened laser gain media, ASE and parasitic oscillation modes can be effectively suppressed.

Abstract: The invention writes a fiber Bragg grating (FBG) onto a fiber. The invention uses a phase mask to separate an input beam into two beams, and possibly encode each of the two beams with phase information. The invention then uses one or more modulators to possibly encode phase information onto the two beams. An image relay telescope collects the two beams and causes the two beams to interfere with each other to form the FBG on the fiber according to the phase information encoded on the two beams. The image that is incident onto the input surface of the telescope is re-imaged at the output surface of the telescope. Thus, either the phase mask or the modulators, or a combination of both can encode phase information onto the two beams.