Passively mode-locked fiber laser based on ethylene glycol

• DOI: 10.1016/j.rinp.2024.107670
• Publication Date: 2024-04-13T04:03:05Z
• Authors: Wenyan Zhang; Huijie Jiang; Lei Zheng; NanNan Liu; Xiaodong Zhang; Kun Yang; Li Zhan
• Keywords: Fiber lasers; Physics; QC1-999; 0103 physical sciences; Optical solitons; 0210 nano-technology; Ethylene glycol; Pulse laser

A passively mode-locked Er-doped fiber laser employing ethylene glycol as a saturable absorber (SA) has been proposed and experimentally validated. The ethylene glycol-SA is fabricated by filling the space between the end facets of two optical patch cords inserted into a cannula with ethylene glycol. Utilizing such an SA with a modulation depth of 9.6 %, stable mode-locking operation are manifested in the laser cavity, including the production of bright pulse and bright-dark pulse pair. The generated bright pulse has a center wavelength at 1562.28 nm, a 3 dB bandwidth of 0.21 nm, a repetition frequency of 20.24 MHz, and a signal-to-noise ratio (SNR) of 57 dB. Through precisely manipulating the polarization state and the pump power in the laser cavity, the bright-dark pulse pairs can be successfully attained at the same repetition frequency. This is the first demonstration of a passively mode-locked fiber laser utilizing ethylene glycol as the saturable absorber. Due to their superior optical absorption characteristics, low cost, simplicity in fabrication and non-volatile nature, ethylene glycol-SAs have enormous potential in the field of nonlinear optics and ultrafast photonics.