Polarization switching in a mid-infrared Er:YAlO₃ laser

Area of Science:

• Solid-state laser physics
• Materials science
• Quantum optics

Background:

• Erbium-doped materials are crucial for laser applications.
• Yttrium aluminum perovskite (YAlO₃) offers unique crystal properties.
• Mid-infrared lasers are valuable for spectroscopy and sensing.

Purpose of the Study:

• To investigate the mid-infrared emission properties of Er³⁺-doped YAlO₃.
• To characterize the laser performance of Er:YAlO₃.
• To understand polarization dynamics in the material.

Main Methods:

• Polarization-resolved spectroscopy of Er³⁺ in YAlO₃.
• Laser experiments using Yb-fiber laser pumping.
• Analysis of stimulated emission cross-section and laser parameters.

Main Results:

• Stimulated emission cross-section of 0.20 × 10^-20 cm² at 2919 nm for E ‖ c.
• 1.36 W output power at 2919 nm with 31.4% slope efficiency for 10 at.% Er:YAlO₃.
• Low laser threshold of 33 mW and linear polarization achieved.
• Observed pump-induced polarization switching attributed to excited-state absorption.

Conclusions:

• Er:YAlO₃ is a promising material for efficient mid-infrared lasers.
• The observed polarization switching offers insights into laser dynamics.
• Further research can optimize Er:YAlO₃ for advanced laser applications.