Intermodal Nonlinear Optics - DURIP
Abstract
Laser source engineering, whether for high-power applications ranging from underwatercommunications, sensing and directed energy applications, or for quantum source engineeringand networking modalities, critically relies on on-demand production of pulses of light of thedesired energy and wavelength across the electromagnetic spectral range. Covering this vastdiversity of energy as well as wavelengths is typically achieved with low efficiency, bulk,alignment-sensitive free-space sources such as the ubiquitous optical parametric oscillator oramplifier. The beam quality of such sources is often poor, which impacts applications in whichfree-space propagation of the beam is required, as well as for cases in which fiber-coupling isnecessary. For high power applications, this results in critical loss of power, and for quantumapplications, the loss directly reduces key rates for communications applications.Optical fibers are an attractive alternative, but until recently, were unable to scale power ortranslate wavelengths with independent, versatile control. This has changed with the recentadvent of multimode nonlinear optics a field in which stable ensembles of higher order spatialmodes of a multimode fiber interact with each other to break this dispersion (hence phasematching, leading to wavelength) versus mode area (hence power) trade-off. The emerging fieldof multimode fiber optics provides several other advantages such as (1) a ready platform inwhich mode diversity can be used to scale information capacity of quantum as well as classicalcommunications networks; (2) rewrite the rules of light-matter interactions, and hence offer newmodalities for sensing and spectroscopy due to the fact that modal control translates to thecontrol of angular, especially orbital angular momentum (OAM) control as well as the control oflinear momentum of light.The PI has led several inventions in this field, including the first demonstration of Besselbeams in optical fibers, and the first demonstration of km-length-scale OAM beam transmissionin optical fibers. He has multiple related programs that continue to advance the field, such as (a)the Vannevar Bush Faculty Fellowship studying fundamental interactions between light andmatter in the presence of OAM selection rules; (b) an ONR program studying the use ofintermodal four-wave mixing to scale the power of blue fiber lasers; (c) an AFOSR-BRI programstudying Raman, Brillouin and parametric processes enabled by intermodal phase matching;(d) a NSA program studying the use of OAM modes for information capacity scaling in datacenters; and (e) a NSF program studying the use of OAM fiber modes for nanoscale microscopy.DURIP funds requested herein entail the development of a high-power spatial modesculpting system using a high-power spatial light modulator a high-power pump laser, and aglass processing system that enables fabrication of devices for testing by DoD collaborators.These purchases will facilitate the investigations in all aforementioned programs, but especiallyimpacting the Vannervar Bush Faculty Fellowship, ONR blue laser and AFOSR-BRI programs.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 29, 2020
- Source ID
- N000142012282
Entities
People
- Siddharth Ramachandran
Organizations
- Boston University
- Office of Naval Research
- United States Navy