Compact External-cavity DPAL pump system with atomic wavelength stability

The diode-pumped alkali laser, also called DPAL, is one of two technologies currently under consideration for meeting the US Defense Department’s requirement for a megawatt laser by 2030 that is electrically powered, operable from an aircraft or drone, and capable of intercepting hypersonic weapons or ballistic missiles during their boost-phase. Research programs at Lawrence Livermore National Laboratory and at three Air Force installations seek to scale-up the output power capability of DPAL, however progress has stalled in recent years primarily due to the lack of efficient pump laser technology with high spectral brightness. For 16 years, our team of engineers and scientists have been inventing and refining laser architectures for optical pumping of alkali vapors in flowing gases. This is exactly the process used for DPAL. Two years ago, we developed a whole new class of laser with ultra-high spectral brightness that improves performance by a factor of ten. In our Phase I effort we showed that the meter-long system we originally implemented can be shrunk to just a few inches in length and be made more robust without compromising performance. In this Phase II proposal, we describe a base period to integrate our new compact, robust design into a commercial 3kW package. We will deliver a second 3kW package to our customer at the Center for Directed Energy of the Air Force Institute of Technology. With an additional million-dollar, twelve-month option, we will assemble a 20kW module, recreate our DPAL gas circulator, and demonstrate for our customers one of the most powerful, if not the most powerful, DPAL in the world.