High-energy nanosecond parametric source at 2.7  µm.

Area of Science:

• Laser Physics
• Nonlinear Optics

Background:

• Optical parametric oscillators (OPOs) and amplifiers (OPAs) are crucial for generating tunable laser light.
• Developing high-energy sources in the mid-infrared (mid-IR) is essential for various spectroscopic and material processing applications.

Purpose of the Study:

• To report a high-energy nanosecond KTiOAsO4-based OPO and OPA system.
• To demonstrate its capability for pumping few-cycle optical parametric chirped-pulse amplification (OPCPA) in the long-wave infrared (LWIR) spectral regime.

Main Methods:

• Utilized a 1064-nm, injection-seeded, Q-switched Nd:YAG laser as the pump source.
• Employed potassium titanyl arsenate (KTiOAsO4) crystals in the OPO and OPA system.
• Operated the system in two modes: 1-ns and 10-ns pulse durations.

Main Results:

• Achieved an output energy of 10.5 mJ at 2726 nm with a 1.2 ns pulse duration and 2.8 nm spectral width.
• Demonstrated 10-ns pulse operation with an output energy of 25 mJ.
• Characterized beam quality with M² values of 2.4 (1.2 ns) and 2.8 (10 ns).

Conclusions:

• The developed KTiOAsO4-based OPO and OPA system is a high-energy source for mid-IR generation.
• The system effectively pumps LWIR OPCPA, offering versatile pulse durations for different applications.