Opto-Electronic Advances (Sep 2023)

Broadband and continuous wave pumped second-harmonic generation from microfiber coated with layered GaSe crystal

  • Zhen Hao,
  • Biqiang Jiang,
  • Yuxin Ma,
  • Ruixuan Yi,
  • Xuetao Gan,
  • Jianlin Zhao

DOI
https://doi.org/10.29026/oea.2023.230012
Journal volume & issue
Vol. 6, no. 9
pp. 1 – 10

Abstract

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The conversion-efficiency for second-harmonic (SH) in optical fibers is significantly limited by extremely weak second-order nonlinearity of fused silica, and pulse pump lasers with high peak power are widely employed. Here, we propose a simple strategy to efficiently realize the broadband and continuous wave (CW) pumped SH, by transferring a crystalline GaSe coating onto a microfiber with phase-matching diameter. In the experiment, high efficiency up to 0.08 %W-1mm-1 is reached for a C-band pump laser. The high enough efficiency not only guarantees SH at a single frequency pumped by a CW laser, but also multi-frequencies mixing supported by three CW light sources. Moreover, broadband SH spectrum is also achieved under the pump of a superluminescent light-emitting diode source with a 79.3 nm bandwidth. The proposed scheme provides a beneficial method to the enhancement of various nonlinear parameter processes, development of quasi-monochromatic or broadband CW light sources at new wavelength regions.

Keywords