摘要 |
A system for automatically aligning a high power laser. The optical train of the high power laser includes an unstable resonator cavity, a two axis, gimballed turning mirror and a extraction mirror. The autoalignment system utilizes a HeNe laser to propagate an alignment beam coaxial with, and prealigned with, the high power beam. The reference beam traverses the same optical path as the main, high power beam, propagating through all of the relay optics of the laser train. This allows angular deviations in the pointing direction of the main beam to be inferred from the angularity of the reference beam. At the downstream end of the laser train, the extraction mirror functions as an optical interface, pointing the main beam in the preferred output direction and extracting the reference beam by means of a central passageway through the extraction mirror. The extracted reference beam is directed on a path incident to a null angle sensor. The angularity of the extracted reference beam is detected by the null angle sensor. Any angular displacement results in a corresponding error signal. The error signals are translated by alignment system servo electronics into correcting tilt adjustments to the gimballed turning mirror, realigning the main beam as well as the coaxial reference beam.
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