SBIR-STTR Award

Compact External-cavity DPAL pump system with atomic wavelength stability
Award last edited on: 10/15/21

Sponsored Program
SBIR
Awarding Agency
DOD : AF
Total Award Amount
$1,147,291
Award Phase
2
Solicitation Topic Code
AF193-CSO1
Principal Investigator
Jan H Distelbrink

Company Information

Xemed LLC (AKA: Xemed)

16 Strafford Avenue
Durham, NH 03824
   (603) 868-1888
   info@emed.com
   www.xemed.com
Location: Single
Congr. District: 01
County: Strafford

Phase I

Contract Number: FA8649-20-P-0185
Start Date: 12/12/19    Completed: 12/12/20
Phase I year
2020
Phase I Amount
$49,988
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.

Phase II

Contract Number: FA8649-20-C-0092
Start Date: 5/1/20    Completed: 8/31/21
Phase II year
2020
Phase II Amount
$1,097,303
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