摘要 |
A photosensitive optical fiber being scanned by an ultraviolet beam to form an optical filter is aligned with the beam by detecting fluorescence produced in the fiber. The relative position of the fiber and beam is made to oscillate in a direction cutting across the scanning direction. Misalignment is corrected according to the phase relationship between the fluorescence detection signal and the oscillation, permitting the alignment to be controlled accurately regardless of the beam dimensions, scanning distance, scanning rate, and natural fluorescence variations.
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