Low SWAP Sources for High-Power Blue Communications
Abstract
"Underwater and Submarine optical sensing technologies, (e.g. LIDAR) depend on the ability to propagate light through water. Since ocean water loss minimizes in the blue spectral range, it would be critical to develop sources that are powerful enough to overcome the scattering and turbulent nature of the un-guided medium in this wavelength range. Such sources would need the ability of being efficiently modulated while also being compact and lightweight to facilitate deployment on aircrafts.Here, we propose a wavelength translator that is all fiber, can handle high energies, and is highly efficient compared to existing technologies. Following our demonstrations over the last few years, it is now well known that higher order mode (HOM) fibers offer significant mode area, and hence power, scaling, as well as dispersion control. The scheme proposed here exploits these properties to enable generation of light directly out of fiber in the spectral range of 880-980 nm, which when doubled with an appropriate nonlinear crystal, yields a high energy source at 440-490 nm, covering a range of wavelengths of interest in underwater sensing and communications applications. Our design methodology utilizes conventional fiber lasers emitting in the 10xx nm range, followed by our specialty HOM fiber that yields the desired near-infra-red emission, which precedes the final frequency doubling step that is capable of simultaneously converting the structured HOM output into a Gaussian at half the wavelength.Given the inherent power scalability and efficiency of our platform, we expect to develop the proof of concept of a laser capable of emitting 10 kW peak power pulses (which, when obtained with 100 ns long pulses, yields millijoule pulse energies) in the blue spectral range with optical efficiencies in the range of 30-37%. This represents an order of magnitude improvement in efficiency over bulky optical parametric oscillators (currently the only viable options for accessing the blue spectral range with high energy lasers) while providing for a lightweight compact source that is field-deployable."
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 29, 2020
- Source ID
- N000142012226
Entities
People
- Siddharth Ramachandran
Organizations
- Boston University
- Office of Naval Research
- United States Navy