High-power OPCPA generating 1.7 cycle pulses at 2.5 µm

Area of Science:

• Laser Physics
• Nonlinear Optics
• Ultrafast Science

Background:

• Mid-infrared (mid-IR) ultrashort pulse generation is crucial for various spectroscopic applications.
• Traditional few-cycle systems in the mid-IR often rely on nonlinear pulse compression, which can degrade pulse quality.
• Achieving high-power, few-cycle pulses in the mid-IR without nonlinear compression presents a significant challenge.

Purpose of the Study:

• To demonstrate a novel high-power mid-infrared optical parametric chirped-pulse amplifier (OPCPA) system.
• To generate ultrashort pulses with durations in the few-cycle regime without employing nonlinear pulse compression.
• To achieve high average power and high peak power in the mid-IR spectral region.

Main Methods:

• Utilizing a carefully designed gain profile in each amplification stage of the OPCPA.
• Implementing precise control over signal dispersion throughout the entire amplification system.
• Employing a pulse shaper in the seed beam to precisely manage the spectral phase of the output pulses.

Main Results:

• Generation of 14.4 fs pulses centered at 2.5 µm.
• Achieved an average output power of 12.6 W at a 100 kHz repetition rate.
• Obtained a high peak power of 6.3 GW with a clean temporal profile, notably without nonlinear pulse compression.

Conclusions:

• The developed OPCPA system offers a robust method for generating high-power, ultrashort mid-IR pulses.
• The absence of nonlinear pulse compression preserves excellent pulse quality and temporal profile.
• This technology advances the capabilities for research requiring high-intensity, few-cycle mid-IR radiation.