Open-loop spectral beam combining based on parity-time-symmetric double-ridge stripe laser diodes

In this paper, a polarization full-feedback open-loop spectral beam combining (PFF-SBC) structure based on double-ridge stripe semiconductor parity-time-symmetric laser diodes (PTLDs) is proposed and demonstrated.The beam quality of the PTLD is optimized, and the combining efficiency is improved using the methods of polarization separation and full feedback.The maximum output power is up to 2.71 W, which leads to a spectral beam combining efficiency of 83.4% and a grating diffraction efficiency of 95.51% under continuous current operation at a current of 2.3 A. Additionally, the brightness of the SBC module is 116.2MWcm -2 sr -1 at a current of 1.6 A, which is 3.5 times that of a single PTLD.The PFF-SBC strategy provides, to our knowledge, a new approach for increasing the beam brightness of PTLDs.