High-Energy Mode-Locked Pulse Er-Doped Fiber Laser-Based GeTe as Saturable Absorber.

Area of Science:

• Optics and Photonics
• Materials Science
• Laser Physics

Background:

• Erbium-doped fiber lasers are crucial for various applications, including telecommunications and spectroscopy.
• Achieving high-energy, mode-locked operation with high conversion efficiency remains a key challenge in fiber laser development.
• Saturable absorbers (SAs) are essential components for initiating and stabilizing mode-locking in lasers.

Purpose of the Study:

• To investigate the performance of a germanium telluride (GeTe)-based saturable absorber (SA) for high-energy mode-locked Er-doped fiber lasers.
• To achieve high optical-to-optical conversion efficiency in an Er-doped fiber laser system.
• To demonstrate the suitability of GeTe as an SA for generating high-energy pulses.

Main Methods:

• Fabrication and integration of a GeTe-based SA into an Er-doped fiber laser cavity.
• Utilizing a polarization controller (PC) to optimize mode-locking parameters.
• Characterization of laser output, including central wavelength, repetition frequency, output power, and single-pulse energy.

Main Results:

• A high-energy, mode-locked Er-doped fiber laser was successfully demonstrated using a GeTe-based SA.
• The laser operated at a central wavelength of 1533.1 nm with a fundamental repetition frequency of 1.58 MHz.
• Maximum average output power reached 50.48 mW with a single-pulse energy of 32 nJ, achieving an optical-to-optical conversion efficiency of approximately 11.2%.

Conclusions:

• Germanium telluride (GeTe) exhibits excellent performance as a saturable absorber for mode-locked fiber lasers.
• GeTe-based SAs play a critical role in enabling high-energy pulse generation in fiber laser systems.
• The developed laser system shows significant potential for applications requiring high-energy ultrashort pulses.