Polarization-separated feedback spectral beam combining source.

A novel, to the best of our knowledge, structure for spectral beam combining (SBC) is proposed, utilizing a polarization-separated feedback (PSF). A polarization separation element is introduced to separate the laser beam into a TE-polarized light and a TM-polarized light. The lower-power light is selected as the external feedback to adjust the resonant wavelength, while the other light is combined spectrally. Compared to the conventional SBC source with a similar feedback, the power and efficiency of the PSFSBC are improved by approximately 20%. Additionally, the beam quality in the non-SBC direction is optimized by 10%, and the power on the output coupler is reduced to nearly one-third. This provides an effective method for achieving an optimized SBC performance.