High-Average Power, High-Energy, 2-um Laser Source for High-Harmonic Generation

Pulsed, 100 mJ, kHz-rate, picosecond lasers in the 2-um wavelength range are of a critical importance to the development of the next-generation, laser-driven X-ray sources based on high-harmonic generation. The 2-um lasers are needed as efficient pump sources for parametric-generation of energetic, mid-IR femtosecond pulses, which in turn drive the high-harmonic-generation process. Current pump laser technology operates at shorter wavelengths, limiting parametric-generation efficiency, and, ultimately, the powers available in the X-ray region. We propose the initial development of a high-pulse-energy, high-repetition-rate, picosecond, 2-um laser source. The device will be based on a master-oscillator-amplifier architecture, utilizing a passively mode- locked holmium-doped solid state laser oscillator and robust, high-power, modular Ho:YLF solid state amplifiers to scale the output to ~100 mJ at ~1 kHz. We plan to design and build a deliverable, packaged system in the Phase II program. Commercial Applications and Other Benefits: The primary application of the proposed laser technology is for laser driven X-ray sources based on high-harmonic generation. The modular architecture implemented in our system design allows easy configuration to set the power output at the level required by the user. Lasers with such a high pulse energy, kHz-rate, picosecond pulsewidth operating at wavelength longer than 2 um are not commercially available at the present time.