Measurements of the gain medium temperature in an operating Cs DPAL

Area of Science:

• Laser physics and optical diagnostics
• High-temperature phenomena in gas lasers
• Quantum optics and atomic vapor applications

Background:

• Cesium Direct Potentially Amplifying Lasers (Cs DPAL) are crucial for high-power laser generation.
• Understanding heat deposition is vital for optimizing DPAL performance and longevity.
• Previous studies lacked precise in-situ temperature measurements of the gain medium.

Purpose of the Study:

• To investigate the temperature distribution within the Cs DPAL gain medium.
• To quantify heat deposition sources, including lasing and non-lasing processes.
• To correlate temperature rise with laser performance degradation.

Main Methods:

• Utilized a Mach-Zehnder interferometer for contactless temperature measurement.
• Employed a static cell setup for controlled Cs DPAL operation.
• Analyzed heat deposition by comparing lasing and non-lasing conditions.

Main Results:

• Achieved contactless temperature measurements of the Cs DPAL gain medium.
• Recorded maximum temperatures approaching 700°C, indicating significant thermal load.
• Identified quenching as the primary heating mechanism, responsible for up to 85% of the total heat deposition.
• Observed a direct correlation between high temperatures and degraded laser performance.

Conclusions:

• Contactless interferometric thermometry is effective for monitoring Cs DPAL gain medium temperatures.
• Quenching significantly contributes to thermal management challenges in DPALs.
• Mitigating heat from quenching is essential for improving Cs DPAL efficiency and stability.