Author(s): Li, M (Li, Ming); Wang, QH (Wang, Qiuhua); Li, YB (Li, Yaobin); Qiu, PP (Qiu, Pingping); Meng, HL (Meng, Hongling); Xie, YY (Xie, Yiyang); Kan, Q (Kan, Qiang)

Source: JOURNAL OF MODERN OPTICS DOI: 10.1080/09500340.2022.2032441 Early Access Date: FEB 2022

Abstract: A polarization-stabilized fundamental mode vertical cavity surface emitting laser (VCSEL) was developed for a coherent population trapping (CPT) Cs atomic clock. The VCSEL achieved a single stabilized polarization state through a directly-etched surface grating structure on the surface. The device polarization characteristics of different surface grating parameters were analysed using the finite-difference time-domain (FDTD) method. For the fundamental transverse mode condition, the lasing wavelength corresponded to the Cs atom's D-1 line. Owing to the polarization-dependent reflectivity of surface gratings, the VCSEL's orthogonal polarization suppression ratio (OPSR) exceeded 20 dB. Since the surface grating eliminated the degeneracy of the two orthogonal linear polarization fundamental modes, a linewidth of approximately 53 MHz for the VCSEL could be obtained using the delayed self-homodyne method. A 7.6 GHz modulation bandwidth satisfied the atomic clock's bandwidth requirement. We introduced the directly-etched surface grating VCSEL to the Cs atomic clock, and measured the CPT resonance signal.

Accession Number: WOS:000754149300001

ISSN: 0950-0340

eISSN: 1362-3044

Full Text: https://www.tandfonline.com/doi/full/10.1080/09500340.2022.2032441