High Power Laser and Particle Beams, Volume. 35, Issue 4, 041011(2023)
Beam combining/splitting technology of sodium beacon laser for generating sodium guidestars constellation
A polarization and sequence incoherent combining technology of pulsed laser beam is introduced. A 100 W level microsecond-pulse all-solid-state sodium beacon laser is performed, via combining two independent 50 W level 589 nm lasers at 500 Hz to be one beam by a polarized coupler. Through a pulsed laser synchronizing and delay controller, the two pulsed laser beams are added successfully at time sequence, and the corresponding repetition rate is up to 1 kHz. The beam quality factor M2 of the combined laser is about 1.41, maintaining at almost equal level with one of two laser beams, and the beam pointing stability is measured to be about 40 μrad, which can well meet the requirements at the time of laser guide star testing. Compared with the coherent beam combining, the approach of polarization and sequence incoherent combining has high efficiency, simple combination, and no specific restriction on phase and frequency spectrum, providing a new way for pulsed laser power scaling. Based on a self-proposed precise polarized splitting technology, four beams of (25 W/beam) μs-pulsed yellow laser are projected up to the sodium layer through one launching telescope at Lijiang Observatory, and successfully generate four sodium guidestars, which could promote the development of multi-conjugate adaptive optics systems on large-aperture ground-based telescopes.
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Qi Bian, Yong Bo, Junwei Zuo, Qinjun Peng. Beam combining/splitting technology of sodium beacon laser for generating sodium guidestars constellation[J]. High Power Laser and Particle Beams, 2023, 35(4): 041011
Category: Laser Beam Combining Technology
Received: Sep. 25, 2022
Accepted: Dec. 12, 2022
Published Online: Apr. 18, 2023
The Author Email: Bo Yong (boyong@mail.ipc.ac.cn)