High-efficiency fluoroindate glass fiber laser.

Area of Science:

• Materials Science
• Optics and Photonics
• Laser Physics

Background:

• Mid-infrared (MIR) fiber lasers are crucial for spectroscopy and sensing.
• Dysprosium (Dy3+)-doped glasses are promising for MIR laser generation.
• Fluoroindate glasses offer good optical properties for MIR applications.

Purpose of the Study:

• To demonstrate high-efficiency operation of a Dy3+-doped fluoroindate glass fiber laser in the 3 µm region.
• To achieve narrow-linewidth wavelength stabilization for the MIR fiber laser.
• To establish a foundation for power-scaling of MIR fluoroindate glass fiber lasers.

Main Methods:

• In-band pumping of a Dy3+-doped fluoroindate glass fiber laser at 2.83 µm using an Er3+-doped fluorozirconate glass fiber laser.
• Fabrication and characterization of a Dy3+-doped fluoroindate glass fiber.
• Inscribing a high-reflectivity fiber Bragg grating (FBG) directly into the Dy3+-doped fluoroindate glass for wavelength stabilization.

Main Results:

• Achieved a slope efficiency of 82% for the free-running laser, nearing the theoretical Stokes limit.
• Recorded a maximum output power of 0.36 W, the highest reported for a fluoroindate glass fiber laser.
• Demonstrated narrow-linewidth wavelength stabilization at 3.2 µm using a novel Dy3+-doped fluoroindate glass FBG.

Conclusions:

• The developed Dy3+-doped fluoroindate glass fiber laser exhibits high efficiency and output power in the MIR.
• The use of a custom-inscribed FBG enables effective wavelength stabilization.
• These findings pave the way for advanced MIR fiber laser systems based on fluoroindate glass technology.