Signal-to-idler energy conversion from 1.9 to 2.3 µm by transient stimulated Raman chirped-pulse amplification

Area of Science:

• Laser Physics
• Nonlinear Optics

Background:

• Optical parametric chirped-pulse amplification (OPCPA) is a key technique for generating high-energy ultrashort pulses.
• Stimulated Raman amplification (SRA) offers wavelength conversion and amplification capabilities.

Purpose of the Study:

• To demonstrate a novel approach for enhancing idler energy buildup in the short-wave infrared (SWIR) range.
• To combine OPCPA and transient SRA for improved ultrashort pulse generation.

Main Methods:

• Utilized OPCPA output pulses (1800–2000 nm signal, 2100–2400 nm idler) as pump and Stokes seed for SRA.
• Employed a KGd(WO4)2 crystal for the stimulated Raman amplifier.
• Pumped both OPCPA and supercontinuum seed with ~1.2-ps pulses from a Yb:YAG chirped-pulse amplifier.

Main Results:

• Achieved a 33% increase in idler energy using transient stimulated Raman chirped-pulse amplification.
• Generated nearly transform-limited ~53-fs pulses after compression.
• Demonstrated efficient energy buildup in the SWIR range.

Conclusions:

• The combination of OPCPA and transient SRA is an effective strategy for boosting idler energy in the SWIR.
• This approach yields high-quality, compressed ultrashort pulses.
• The developed technique shows promise for advanced spectroscopic and nonlinear optical applications.