Cascade gaseous Raman laser at 2.6 μm in sequential multiple-pass cells

Area of Science:

• Optics and Photonics
• Laser Physics
• Nonlinear Optics

Background:

• Mid-infrared (MIR) lasers are crucial for various applications, including spectroscopy, remote sensing, and medical treatments.
• Efficient generation of MIR radiation, particularly at wavelengths around 2.6 μm, remains a significant challenge in laser technology.

Purpose of the Study:

• To develop an efficient cascade gaseous stimulated Raman scattering (SRS) laser system for generating 2.6 μm mid-infrared radiation.
• To investigate the performance and characteristics of a dual-cell SRS configuration for extending laser wavelengths.

Main Methods:

• Employed a two-stage, seven-pass cell configuration for gaseous SRS.
• Utilized a 1064 nm Nd:YAG laser as the pump source, converted to 1907 nm in a H2-filled cell.
• Used the 1907 nm output to pump a CO2-filled cell, generating the final 2594 nm output.

Main Results:

• Achieved efficient generation of 2594 nm mid-infrared laser radiation.
• Optimized operation yielded 21.6 mJ output energy with a 23.7% pump-to-output conversion efficiency (PCE).
• Measured a peak power of 2.63 MW and a beam quality factor (M2) of 2.46 for the 2594 nm output.

Conclusions:

• The dual-cell cascade SRS laser system provides an effective technical route for producing high-peak-power MIR lasers.
• This approach demonstrates the feasibility of extending laser wavelengths into the targeted mid-infrared spectral region.
• The achieved performance metrics highlight the potential of this method for MIR laser applications.