Changchun Institute of Optical Machinery and Physics (CIPM), Chinese Academy of Sciences (CAS), has reported that the research team on high-power semiconductor lasers at CIPM, under the leadership of academician Wang Lijun and researcher Ning Yongqiang, has carried out research on advanced narrow-linewidth semiconductor lasers and key technologies in recent years.
Recently, Associate Researcher Chao Chen of the team reported an 852nm narrow linewidth, linearly polarized semiconductor laser based on an external optical feedback structure. The laser structure achieves a high line-polarization, narrow linewidth laser output of over 30 dB polarization extinction ratio and as low as 2.58 kHz by introducing a femtosecond laser-induced birefringent Bragg grating filter and integrating it with a hybrid of high-polarization-correlation semiconductor gain chips using polarization-mode-selective feedback and injection-locking techniques.
Fig. (a) Excitation spectral characteristics of the laser, (b) Polarization extinction ratio variation characteristics with injection current (the inset shows the laser power measured by different waveplate rotation angles of the laser), (c) beat-frequency power spectrum and its fitting curve of the laser linewidth measured by time-delayed self-absorption, and (d) Lorentzian linewidth numerical simulation and test results.
The laser can be used as a potential atomically pumped light source for quantum precision measurement systems and, based on previous research in radiation-resistant, narrow-linewidth lasers, it is also promising to be used in cold atom quantum experimental systems in space environments, both on-board and on-board arrows.
