A few-picosecond and high-peak-power passively mode-locked erbium-doped fibre laser based on zinc oxide polyvinyl alcohol film saturable absorber

Abstract

This paper demonstrates a few-picosecond and high-peak-power mode-locked fiber laser, using an erbium-doped fiber as a gain medium and zinc oxide (ZnO) element as a new passively saturable absorber (SA). The ZnO element was synthesized using a seeding solution and amended with a polyvinyl alcohol to form a film. The ZnO has been identified as an ideal SA due to its high nonlinear optical response, high sustainability to damage threshold, and fast recovery time. Self-started mode-locked laser pulses have been generated at a relatively low pump power of 42 mW with a fundamental repetition rate and pulse duration of 3.26 MHz and 2.60 ps, respectively. The proposed laser operates at 1599.5 nm with a 3 dB spectral bandwidth of 1.12 nm. A maximum output power, pulse energy, and peak power of about 6.91 mW, 2.12 nJ, and 0.82 kW, respectively, are obtained at a maximum pump power of 159 mW. From these findings, we confirm that the proposed laser can be viewed as a promising light source in the emerging optical communication system.

Recent Progress on Metal‐Based Nanomaterials: Fabrications, Optical Properties, and Applications in Ultrafast Photonics

“…In 2018, Alani et al proposed the first mode-locked EDFL by using ZnO as SA, where the self-started pulses were generated with a 2.6-ps width at the repetition rate of 3.26 MHz. [220] In 2019, Husin et al integrated ZnO-SA into an EDFL as Q-switcher, in which the 0.46-mW output power and 18.13-nJ pulse energy were received at the maximum pump power of 48.58 mW. [221] Moreover, a ZnO SA was also applied to a laser in 2-μm band and d) RF spectrum at 2.5 kHz and 50 MHz resolution.…”

A novel technique for the fabrication of a saturable absorber for fiber lasers: pulsed laser deposition

“…The ZnO with a direct band-gap (3.4 eV) and a short recovery time (1-5 ps) makes it a suitable candidate for an ideal SA. Most recently, significant efforts have been devoted to preparing SAs using chemical vapor deposition [8], micromechanical cleavage [9], liquid phase epitaxy [10], nano-powder [11] and solution method techniques [12][13][14][15] and then incorporating the prepared nanostructures/thin-film into a ring cavity by inserting them between the fiber ferrules. However, thin films designed to act as SAs prepared using these techniques offer a few disadvantages such as complicated optical alignment, short term stability, low damage threshold, environmental sensitivity and less control of the precise thickness of nanomaterial/thin-film on the fiber ferrule.…”

CsPbBr3 Perovskite Nanocrystals for a Q-Switched Pulsed Fiber Laser in the C-Band Region

“…24 TMDs and TMOs generally have large band gaps. 25 Furthermore, BP is easily oxidized, 26 and Pdots require complex tuning in broadband operation. 22 Therefore, it is of great significance to explore new SA materials for realizing potential applications in a Q-switched pulsed laser.…”