100W Mode-locked Green Laser for GaAs Photoemission Guns

To address the DoE need for a high-power laser source used for synchronous photoinjection of GaAs photoemission guns, AdValue Photonics proposes to develop a radio-frequency synchronized 100W mode-locked green laser source at a GHz rate. Previously-demonstrated GHz-rate modelocked solid-state/fiber lasers suffer from a reliability issue due to the use of fragile free-space bulk optics for their laser cavities. We propose to develop an all-fiber high-power laser system, which can be synchronized to an external GHz-rate reference signal. Our proprietary high-efficiency rareearth- doped glass fiber technology enables us to develop a robust high-power GHz-rate modelocked fiber laser system. In the Phase I effort, several key concepts of the proposed technology have been demonstrated. The major Phase I achievements include the demonstration of a GHz-rate mode-locked Yb-doped fiber laser, the demonstration of nearly 100W laser out power amplification and >10J-level femtosecond chirped pulse amplification with >20dB gain in 20-30cm long Yb-doped fiber. With these well-demonstrated concepts, we will be able to develop and prototype a highly reliable, compact, high-power, mode-locked green laser for GaAs photoemission guns application. In the Phase II program, we will focus on engineering design for a robust high-power GHz-rate modelocked Yb-doped fiber laser system with a special emphasis on synchronizing the mode-locked laser pulses to an external RF reference signal. The proposed technology will provide a robust light source not only for applications in DoE advanced accelerators, but also for many other scientific and industrial applications, such as optical arbitrary waveform generations, ultra-stable microwave references, telecommunications, material processing, medical surgery, high harmonic generation, and frequency comb spectroscopy.