75 MW few-cycle mid-infrared pulses from a collinear apodized APPLN-based OPCPA

Area of Science:

• Mid-infrared optics
• Nonlinear optics
• Laser physics

Background:

• Optical parametric chirped-pulse amplification (OPCPA) is crucial for generating high-energy ultrashort pulses.
• Existing systems often face limitations in bandwidth, power, or wavelength coverage.
• Mid-infrared (MIR) sources are essential for spectroscopy and nonlinear optics applications.

Purpose of the Study:

• To develop an ultra-broadband OPCPA system operating in the mid-infrared.
• To achieve high average power and short pulse durations from the OPCPA system.
• To demonstrate precise control over the spectral phase of MIR pulses.

Main Methods:

• Utilized a two-stage OPCPA system with apodized aperiodically poled MgO:LiNbO3 (APPLN) crystals.
• Employed a collinear mixing configuration for amplification.
• Incorporated a pulse shaper to manipulate the spectral phase of near-infrared seed pulses.

Main Results:

• Achieved an ultra-broadband OPCPA system centered at 3.4 µm.
• Delivered clean 75-fs pulses with 75 MW peak power.
• Generated a record-high 700 mW average power (7 µJ pulse energy) at a 100 kHz repetition rate.

Conclusions:

• The developed OPCPA system offers a powerful and versatile source for mid-infrared applications.
• The use of APPLN crystals and collinear mixing enables efficient amplification and spectral control.
• This work pushes the boundaries of high-power, ultrashort pulse generation in the mid-infrared spectrum.