Compact external-cavity DPAL pump system with atomic wavelength stability

We recently demonstrated that broadband diode laser arrays can be configured to receive feedback through an atomic line filter (ALF), locking their wavelength and concentrating their spectral power within the narrow absorption profile of rubidium vapor, a one-hundred-fold improvement. We accomplished this, however with a bulky imaging system. During this Phase I project, we will implement a new prototype pump laser architecture that achieves spectral locking via an ALF without the need for the imaging system. This technology will reduce size and complexity of our existing world-class commercial systems for producing hyperpolarized xenon, an inhalable agent for imaging pulmonary function, as well as reducing SWaP for a scalable directed energy weapon. If awarded a Phase II continuation, we will assemble and optimize a 15kW pump laser module, mate it with our proprietary flowing-curtain gas circulator system, and demonstrate a diffraction limited DPAL beam. Although DPAL development programs are underway within the Air Force, our innovation unleashes a cascade of benefits over those efforts, including total absorption of the pump beam at modest gas temperatures, lowered cavity heat load, elimination of chemical cracking of the hydrocarbon quenching-agent, instant time-to-firing (no warm-up transient), and a low-risk power-scaling path to megawatt levels.