High-energy parametric oscillator and amplifier pulsed light source at 2-µm.

Area of Science:

• Lasers and Photonics
• Nonlinear Optics

Background:

• High-energy pulsed lasers are crucial for various scientific and industrial applications.
• Generating tunable wavelengths and specific pulse shapes presents a significant technical challenge.

Purpose of the Study:

• To describe a novel laser system capable of producing high-energy pulses at a 2-µm wavelength.
• To characterize the system's performance in terms of energy, pulse width, spatial, temporal, and spectral properties.
• To evaluate its suitability for driving plasma sources of extreme ultraviolet (EUV) light.

Main Methods:

• Utilized an optical parametric oscillator (OPO) to generate seed radiation.
• Employed an optical parametric amplifier (OPA) pumped by a 1064-nm laser to amplify the signal.
• Incorporated KTP crystals and operated at a 10 Hz repetition rate.
• Characterized the laser output in spatial, temporal, and spectral domains.

Main Results:

• Achieved 800 mJ of combined signal and idler output energy.
• Demonstrated tunable pulse widths from 10-24 nanoseconds.
• Observed saturation effects leading to flat-top spatial and box-shaped temporal profiles.
• Confirmed the ability to image amplified pulses down to sub-100 µm diameters.

Conclusions:

• The developed laser system successfully generates high-energy, tunable 2-µm pulses with desirable beam profiles.
• The system's characteristics make it a promising driver for plasma-based extreme ultraviolet light sources.
• The tunable pulse width and high energy output open possibilities for diverse applications requiring precise laser-matter interactions.