Short-pulsed Q-switched fiber laser using graphene oxide quantum dots based as saturable absorber

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Graphene oxide quantum dots (GOQDs) are synthesized via carbonization and exfoliation of electrospun polyacrylonitrile (PAN) fibers.
• Characterization techniques like FTIR, Raman spectroscopy, and TEM confirm the GOQDs' properties, including functional groups, structural integrity, and size (6 nm).

Purpose of the Study:

• To experimentally investigate the performance of a Q-switched optical fiber laser employing GOQDs as a saturable absorber (SA).
• To characterize the nonlinear optical properties of the fabricated GOQDs for potential use in laser devices.

Main Methods:

• GOQDs were synthesized and characterized using FTIR, Raman, and TEM (including HRTEM).
• A saturable absorber (SA) was fabricated by photodepositing GOQDs onto an optical fiber core.
• Nonlinear characterization (NLC) was performed using the P-scan technique with an erbium-doped fiber amplifier (EDFA) at 1550 nm.
• The GOQDs-based SA was integrated into a fiber laser cavity to achieve Q-switching.

Main Results:

• GOQDs exhibited saturable absorption behavior with a nonlinear susceptibility of [value].
• The fiber laser generated pulsed emission at 1599 nm, with a tunable repetition rate from 2 to 16 kHz.
• A maximum average output power of 1.3 mW was achieved, demonstrating the Q-switched operation.

Conclusions:

• Graphene oxide quantum dots effectively function as saturable absorbers for Q-switched fiber lasers.
• The fabricated GOQDs show promising nonlinear optical properties suitable for pulsed laser applications.
• This work highlights a cost-effective method for producing GOQDs for optoelectronic devices.