100 W 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 (RF) synchronized 100W green fiber laser source with a repetition rate near 1GHz. Although GHz-rate mode-locked solid-state/fiber lasers in the near infrared have been previously demonstrated, which could be used as a laser source for synchronous photoinjection applications, these lasers suffer from a reliability issue due to the use of fragile free-space bulk optics for their laser cavities, not to mention their difficulties in RF synchronization. We propose to develop a low-noise all-fiber laser system fundamentally mode-locked at 1GHz, which can be easily synchronized to an external RF reference signal. It is based on our proprietary glass fiber technology and extensive experience in phase-stabilized GHz-rate mode-locked laser development. In Phase I, we will design and fabricate highly Yb-doped fibers to build short-cavity mode- locked seed laser, and use the high-gain doped fibers to boost the power of the mode- locked 1m fiber laser up to 100W average power, thereby achieve a proof-of-concept demonstration with frequency doubling of the high-repetition-rate mode-locked fiber laser. If the project is carried over into Phase II and Beyond, the proposed technology will provide a robust light source not only for applications in 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.