10 kHz 40 W Ti:sapphire regenerative ring amplifier

Area of Science:

• Laser Physics
• Plasma Physics
• Materials Science

Background:

• Laser-produced plasma (LPP) light sources are crucial for various applications.
• Developing high-average-power laser systems is essential for enhancing LPP source performance.
• Thermal lensing in high-power amplifiers can degrade beam quality and system efficiency.

Purpose of the Study:

• To develop a cryogenically cooled Ti:sapphire regenerative ring amplifier for LPP generation.
• To achieve high average power output from a single-stage Ti:sapphire amplifier.
• To investigate and mitigate the effects of thermal lensing in the amplifier system.

Main Methods:

• Designed and constructed a cryogenically cooled Ti:sapphire regenerative ring amplifier.
• Utilized a 10 kHz, 180 W pump laser.
• Measured amplifier output power before and after compression.
• Characterized the thermal lens focal length at cryogenic temperatures (100 K).
• Implemented a 1 m focal length lens within the resonator to suppress thermal lensing effects.

Main Results:

• Achieved 40 W output power before compression and 26 W after compression.
• Demonstrated the highest reported average-power output from a single-stage Ti:sapphire amplifier.
• Measured an effective thermal lens focal length of 2.2 m at 100 K with 180 W pump power.
• Successfully suppressed thermal lens effects on the resonator mode using an intra-resonator lens.
• Obtained high conversion efficiency across the entire pumping power range without active thermal compensation.

Conclusions:

• The cryogenically cooled Ti:sapphire amplifier provides a high-average-power laser source for LPP generation.
• The implemented resonator design effectively mitigates thermal lensing, ensuring stable performance.
• This system represents a significant advancement in high-power laser development for plasma applications.