N211-063 TITLE: Compact, Efficient, High Power Direct-to-Green Laser Source
RT&L FOCUS AREA(S): Directed energy
TECHNOLOGY AREA(S): Materials / Processes
OBJECTIVE: Develop a highly efficient, direct-to-green laser source for detection of mine and mine-like objects in the Surfzone (SZ) and Very Shallow Water (VSW) regions, Increase the laser efficiency by more than 100% as compared to methods used today.
DESCRIPTION: Current laser sources are very inefficient due to the requirement to obtain the "Green" light from splitting an "Infrared" light source. The generation of green laser light via frequency doubling has typical conversion efficiencies that are ~50% for the process. In addition, the heat dissipation usually requires a method for dissipating the excess energy from the conversion process, upwards of 90%. Research into a relatively new technique of nano-particle doping of fiber lasers shows improved efficiency and power output over current fiber lasers and should be considered when proposing a solution.
In Stride Detect to Engage UAVs requires highly efficient laser sources to meet challenging size, weight, and Power (SWaP) requirements. A direct-to-green source would enable higher power at the same or less SWaP, enabling improved Area Search Rates and Time on Station. For the purposes of estimating SWaP requirements in proposals, the targeted air vehicle is similar to a Bell 407. The laser source will be enclosed in a to-be-designed externally mounted pod with an external diameter of 21 inches and external length of 110 inches. The SWaP will be shared with other sensors. The SWaP potentially available for the laser is 0.75 cubic feet, 60 pounds, and 700 Watts at 28 Volts Direct Current. However, it should be noted that one of the goals of the SBIR is to minimize SWaP. Desired output energy is approximately 500 millijoules at 532 nanometers. Trades will be considered between output energy and SWaP.
The laser shall take into consideration American National Standard Institute (ANSI) Z136.1, Safe Use of Lasers, and Code of Federal Regulations Title 21, Part 1040, Performance Standards for Light-Emitting Products. Other laser requirements, such as pulse width and repetition rate, are based on the chosen receiver. At this time, the Government does not have a receiver in mind but the laser should function with either a 2D Gated or a 3D receiver.
Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. Owned and Operated with no Foreign Influence as defined by DOD 5220.22-M, National Industrial Security Program Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence Security Agency (DCSA). The selected contractor and/or subcontractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances, in order to perform on advanced phases of this contract as set forth by DCSA and NAVSEA in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material IAW DoD 5220.22-M during the advance phases of this contract.
PHASE I: Develop a concept and determine the feasibility of the concept to design a "direct-to-green" laser with improved efficiency over current "green" lasers. Demonstrate the feasibility of methods to manufacture "direct-to-green" lasers, which are manufacturable and able to be amplified in a highly efficient manner. Initial prototype validation of concept will be encouraged. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II.
PHASE II: Based on the results of Phase I efforts and the Phase II Statement of Work (SOW), the company shall develop and deliver a minimum Technology Readiness Level 5 prototype "direct-to-green" laser source suitable for follow-on Government testing (to include flight testing) and validation. The Government may test the laser in accordance with MIL-STD-810 test methods for low pressure (altitude), high temperature, low temperature, acceleration, and vibration for an airborne rotary wing environment. Additional tests may use MIL-STD-461 and MIL-STD-464 to verify electromagnetic compatibility.
Perform laboratory testing and fully characterize the system prototype. Parameters to characterize include bandwidth, pulse width, repetition rate, beam quality, output pulse energy, and output pulse intensity divergence and uniformity.
It is probable that the work under this effort will be classified under Phase II (see Description section for details).
PHASE III DUAL USE APPLICATIONS: The final product should be a ruggedized prototype direct-to-green sensor and software package that can interface with the Coastal Battlefield Reconnaissance and Analysis (COBRA) Sensor. Assist the Government to obtain flight certification on a NAVAIR UAV.
Other applications of blue-green lasers include oceanographic bathymetry, underwater sensing, LiDAR, and communications.
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KEYWORDS: Direct to Green; Airborne Mine Detection; Detection of Ocean Mines; Compact Multi-Spectral Laser; Tactical Unmanned Air Vehicle Sensor; TUAV; Drifting Mines