Picosecond amplification in wide-aperture KrF lasers

Area of Science:

• High-energy laser systems
• Pulsed power technology
• Excimer laser physics

Background:

• Discharge-pumped Krypton Fluoride (KrF) lasers are crucial for applications requiring high-power, short-pulse radiation.
• Optimizing energy extraction and minimizing amplified spontaneous emission (ASE) are key challenges in KrF amplifier design.
• Wide-aperture systems are necessary to handle high energy densities and prevent optical damage.

Purpose of the Study:

• To demonstrate high energy extraction from wide-aperture discharge KrF amplifiers.
• To evaluate the synchronization and ASE levels in a multi-amplifier KrF system.
• To characterize the performance of KrF amplifiers with specific module gain.

Main Methods:

• Utilized two wide-aperture (7 cm x 7 cm) discharge KrF amplifier modules.
• Employed a synchronized system with a time jitter of 1 nanosecond.
• Measured output energy, pulse width, and amplified spontaneous emission (ASE).

Main Results:

• Achieved an output energy of 350 mJ with a pulse width of 20 picoseconds.
• Demonstrated excellent system synchronization with minimal time jitter.
• Limited amplified spontaneous emission (ASE) to 3% of the total energy, attributed to a low small-signal gain of 3.9%/cm.

Conclusions:

• Wide-aperture discharge KrF amplifiers can efficiently deliver high output energy with short pulse durations.
• Effective synchronization is achievable in multi-amplifier KrF systems.
• The low small-signal gain contributes to suppressing amplified spontaneous emission, enhancing beam quality.