Multipass OPCPA system at 100 kHz pumped by a CPA-free solid-state amplifier.

Area of Science:

• Laser Physics and Photonics
• Ultrafast Optics
• Nonlinear Optics

Background:

• High-repetition-rate ultrafast laser systems are crucial for advanced spectroscopic techniques and material processing.
• Optical Parametric Chirped Pulse Amplification (OPCPA) offers a versatile route to generating ultrashort pulses.
• Achieving few-cycle pulse durations at high repetition rates presents significant technical challenges.

Purpose of the Study:

• To develop a compact and efficient few-cycle OPCPA system.
• To utilize a novel pump source for enhanced performance.
• To establish a robust driving source for high-order harmonic generation (HHG).

Main Methods:

• A compact few-cycle 100 kHz OPCPA system was designed.
• The system was pumped by a CPA-free picosecond Nd:YVO₄ solid-state amplifier.
• All-optical synchronization was achieved with an ultra-broadband Ti:sapphire oscillator, employing a two-stage double-pass amplification scheme and chirped mirror compression.

Main Results:

• An exceptional second-harmonic conversion efficiency of nearly 78% was achieved.
• Superfluorescence was effectively minimized and measured via optical cross-correlation.
• Pulses with 8.7 fs duration and 18 µJ energy were successfully demonstrated, yielding a peak power of 1.26 GW.

Conclusions:

• The developed OPCPA system provides a simple yet powerful solution for generating ultrashort pulses.
• The high peak power and repetition rate make it an ideal driving source for HHG.
• This compact system advances the capabilities for ultrafast science research.