Optical parametric amplification of sub-cycle shortwave infrared pulses

Area of Science:

• Optics and Photonics
• Strong-Field Physics
• Nonlinear Optics

Background:

• Few-cycle short-wave infrared (SWIR) pulses are crucial for advanced research in strong-field physics and nonlinear optics.
• Generating ultrashort pulses with controlled characteristics is essential for probing fundamental physical phenomena.

Purpose of the Study:

• To demonstrate the amplification of sub-cycle pulses in the SWIR region.
• To develop a method for precise control over pulse dispersion using a cascaded optical parametric amplifier (OPA) system.

Main Methods:

• Utilized a cascaded BBO-based optical parametric amplifier (OPA) chain.
• Employed a tailored 708 nm pump pulse to achieve a gain bandwidth exceeding one octave in a BBO crystal.
• Implemented a Mach-Zehnder-type interferometer with acousto-optic programmable dispersive filters for spectral component control.

Main Results:

• Successfully amplified sub-cycle pulses in the SWIR region.
• Achieved a gain bandwidth of over one octave.
• Generated 0.73-optical-cycle pulses at 1.8 μm with a pulse energy of 32 μJ.

Conclusions:

• The cascaded BBO-OPA system with spectral control is effective for generating ultrashort SWIR pulses.
• This technique provides a new tool for research in strong-field physics and nonlinear optics.
• The ability to precisely control dispersion enables the generation of few-cycle pulses with high energy.