Progress in Alpha laser characterization-1999

The Alpha laser is a hydrogen fluoride laser (2.7 /spl mu/m) that is a ground based testbed for a Space based laser (SBL). Performance of two recent high power tests has been quantified in terms of power, spectra, near field intensity and phase, far field intensity, and laser jitter. The conclusions were as follows: (1) Misalignments suggested in earlier analyses were found and corrected with improved precision instrumentation. (2) Alpha power performance improved in recent tests because of improvements in alignment and internal clipper positioning. (3) Alpha intensity profile characteristics were improved by the alignment correction. (4) Alpha spectral characteristics show sensitivity to flow conditions. (5) Alpha phase was relatively unaffected by the alignment and flow modifications. Continued investigation of Alpha includes additional testing to explore a predicted improvement in power performance expected from optimization of the flows.