Passively Q-switched erbium-doped fiber laser using coated reduced graphene oxide on arc-shaped single mode optical fiber as a saturable absorber

Abstract

A passively Q-switched erbium-doped fiber laser is demonstrated using saturable absorbers based on the evanescent light field interaction of reduced graphene oxide deposited on ground arc-shaped fiber. The Q-switched operation started at 32.42 mW with a lowest repetition rate of 34.48 kHz and a pulse width of 5.05 µs. A Q-switched pulse is obtained at different levels of pump power with corresponding repetition rates and pulse widths. From the obtained results, the repetition rate increases from 34.48 kHz to 54.10 kHz; in contrast, the pulse width decreases from 5.01 µs to 2.01 µs. The average output power and pulse energy are increased by enhancing pump power from 32.42 mW to 119.5 mW. Additionally, the fundamental frequency is maintained over time with the signal-to-noise ratio of ~55 dB, thus indicating the Q-switched process is stable over a period of 90 min.

Boron carbon oxynitride coated arc-shaped fiber as an optical modulator for passively mode-locked fiber lasers at 1.5 and 2 μm wavelength

“…For the BCNO modulator's preparation, the BCNO solution was prepared by mixing 40 mg of synthesized BCNO with 20 ml of DI water at a 2:1 ratio and then sonicated for 4 h, as in [43]. A single-mode fiber (SMF-28) with a 125 μm cladding diameter was used to prepare the arc-shaped fiber using a polishing wheel technique similar to our previous work [53]. Figure 2(a) shows the microscopic image of an arc-shaped fiber prepared with an insertion loss of 3.2 dB, then a 7.5 μl of prepared BCNO-DI water solution was dropped over the arc-shaped Typically, the signal propagates in the optical fiber core and partially penetrates into the cladding.…”