Remote sensing using slow light imaging for detection of acoustic signatures
Abstract
The objective of this project is to develop optical methods to address the Navy needs of under-water sensing by detecting and imaging acoustic signatures under water. Our approach is to use a combination of temporal and spectral filtering to measure the Brillouinscattering of a pulsed laser propagating through water. The use of relevant laser wavelengths and pulse widths provide underwater lidar capabilities. The temporal filtering is performed by using slow light propagation thought atomic vapors placed in a cell in front of the time gated camera. The narrowband atomic transitions provide high dispersion, and hence a large group delay for laser pulses at the frequencies at which the Brillouin scattering is observed, allowing for delayed imaging of selected spectral features. Bragg transmission gratings are also used to provide tunable narrowband filtering to aid in the rejection of the Rayleigh and Mie scattering from the water molecules and other particles found in the ocean. A series of tunable narrowband nanosecond and picosecond lasers at various repetitions rates (10Hz, 1kHz, 1Mhz) available at the Aerospace Laboratory for Laser, Electromagnetics, and Optics (ALLEMO) at Texas A&M University will be used to propagate light through water, and the Brillouin and Raman signatures will be obtainedfor the purpose of detecting submerged objects through their acoustic and spectral signatures.Approved for Public Release
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 29, 2023
- Source ID
- N000142312466
Entities
People
- Arthur Dogariu
Organizations
- Office of Naval Research
- Texas Engineering Experiment Station
- United States Navy