Holmium-doped 2.1 μm waveguide chip laser with an output power > 1 W

Area of Science:

• Laser physics
• Materials science
• Photonics

Background:

• Glass waveguide lasers offer compact and robust platforms for laser development.
• Holmium-doped glasses are promising for generating light in the short-infrared spectrum.

Purpose of the Study:

• To demonstrate a high-power, tunable, and compact glass waveguide laser.
• To investigate the performance of a holmium-doped ZBLAN waveguide laser.
• To assess its potential for master oscillator applications.

Main Methods:

• Fabrication of an ultra-fast laser inscribed glass waveguide laser using holmium-doped ZBLAN.
• In-band pumping of the waveguide laser with a 1945 nm thulium fiber laser.
• Characterization of the laser's output power, beam quality, and tunability in both monolithic and extended-cavity configurations.

Main Results:

• Achieved over 1.1 W of output power in monolithic operation near 2070 nm with 51% incident slope efficiency.
• Realized over 1 W of output power in a linearly polarized beam using an extended-cavity configuration.
• Demonstrated broad and continuous tunability from 2004 nm to 2099 nm.
• Measured excellent beam quality with M² = 1.08.

Conclusions:

• The holmium-doped ZBLAN glass waveguide laser represents a significant advancement in high-power, tunable short-infrared laser sources.
• Its compact size, excellent beam quality, and broad tunability make it a versatile platform for various photonic applications.
• The laser shows strong potential as a master oscillator for single-frequency and mode-locking systems.