Cryogenic Yb:YAG composite-thin-disk for high energy and average power amplifiers

Area of Science:

• Laser Physics
• Optical Engineering
• Materials Science

Background:

• Traditional high-energy pulsed laser drivers face challenges with amplified spontaneous emission (ASE) and achieving high average power.
• Existing laser systems often struggle with thermal management and maintaining beam quality under high-power conditions.

Purpose of the Study:

• To develop and demonstrate a cryogenic composite-thin-disk amplifier with integrated amplified spontaneous emission (ASE) rejection.
• To overcome limitations of conventional laser systems in high-energy, high-average-power pulsed laser applications.

Main Methods:

• Implementation of a cryogenic composite-thin-disk amplifier design incorporating ASE rejection.
• Utilizing a strict image-relayed 12-pass architecture with an off-axis vacuum telescope and polarization switching.
• Characterization of amplifier performance under identical pumping conditions.

Main Results:

• Achieved a small signal gain of 8 dB, significantly higher than the 1.5 dB gain of an uncapped thin-disk without ASE mitigation.
• Successfully extracted 100 mJ energy at a 250 Hz repetition rate.
• Delivered high beam quality, stretched 700 ps pulses with a narrow 0.6-nm bandwidth.

Conclusions:

• The developed cryogenic composite-thin-disk amplifier effectively mitigates ASE, enhancing gain and beam quality.
• This technology offers a viable solution for high-energy pulsed laser drivers requiring high average power.
• The system demonstrates robust performance for advanced laser applications.