Hybrid laser power combining and beam cleanup system using nonlinear and adaptive optical wavefront compensation

An optical amplification system, comprising:

• a photorefractive medium,
• a signal beam source arranged to direct an s-polarized, substantially diffraction-limited optical signal beam on a path through said medium, and
• a plurality of pump beam sources arranged to direct a plurality of s-polarized non-diffraction-limited optical pump beams into said medium to cross with said signal beam at an approximately 90.degree. beam center crossing angle at successive locations along the signal beam path within said medium, and thereby yield a substantially diffraction-limited amplified signal beam.

An optical distribution system, comprising:

• a waveguide trunk for receiving an input beam, and
• a plurality of asymmetrical waveguide branches that are split from said trunk at different locations along the trunk into n asymmetrical subbranches that terminate at substantially non-zero angles to said trunk in an array that extends generally parallel to said trunk, with at least some of said branches split into parallel pairs of said subbranches at different locations along said branches so that some of said subbranches receive respective portions of said input beam that have experienced more waveguide splits than other subbranches, but none of said subbranches receive respective portions of said input beam that have experienced more than m waveguide splits, where m is the lowest whole number that is greater than or equal to log.sub.2 n and minimizes the accumulation of spontaneous emissions through said distribution system.

An optical phase matching system for matching the phases of each of a plurality of discrete beams, wherein said discrete beams collectively form a combined beam, comprising;

• a beam diverter positioned to divert a minor portion of said discrete beams in said combined beam into a pair of partially overlapping diverted beams, each of said diverted beams having components from each of said discrete beams which are spatially offset from each other, with each of the beam components in one of said diverted beams partially overlapping at least one different beam component in the other diverted beam,
• adjustable phase controls for at least some of said discrete beams, and
• a phase detection system arranged to detect phase differentials between said overlapping portions of said beam components, said phase detector connected to adjust said adjustable phase controls to substantially cancel the detected phase differentials.