MESA PHOTONICS LLC — Department of Energy SBIR Phase II: C53-12a

Description

C53-12a-271285Current electron accelerator technologies are fundamentally limited by the photoinjector, where efficient generation of electron bunches with low emittance is required. Many facilities currently use photocathode materials with excitation by high power ultraviolet pulses, which places extreme demands on system components. Therefore, photocathode materials operating in the visible spectrum are being developed. One impediment to a systematic characterization of these materials is the lack of a suitable high-power excitation laser that is tunable across a wide range with high performance. We propose a laser-driven optical parametric amplification system, which will provide tunable 10’s of picosecond pulses in the visible spectrum at high energy and high repetition rate. Our system emphasizes efficiency in the tunable laser system design to scale to high average power. In Phase I, we demonstrated the feasibility of our proposed technique for the generation of tunable visible pulses for photocathode characterization. We built a prototype novel nonlinear fiber- amplifier seed source and constructed an optical parametric amplifier followed by conversion to tunable visible pulses, at 200kHz repetition rate. Experiments were guided by a numerical model. In Phase II, we will scale our tunable laser system to high average power. We will build a fiber amplifier and parametric amplifier operating at 1 MHz repetition rate, ultimately outputting tunable microjoule pulses of tens of picoseconds duration. Extended numerical models will guide and optimize system performance. Our proposed instrument will provide a valuable tool that can ultimately enable next generation electron accelerator user facilities to operate on a smaller footprint, be built at lower cost, and enhance availability, therefore increasing applications in the medical, research, and security sectors. Our proposed instrument also serves the ultrafast laser market by providing both tunable picosecond pulses, and amplified femtosecond pulses in spectral regions that lack broad gain bandwidths in standard laser materials.