Millisecond-long suppression of spectroscopic optical signals using laser filamentation
Abstract
Ultrashort laser pulse filamentation in air can extend the delivery of focused laser energy to distances greatly exceeding the Rayleigh length. In this way, remote measurements can be conducted using many standard methods of analytical spectroscopy. The performance of spectroscopic techniques can be enhanced by temporal gating, which rejects the unwanted noise and background. In the present work, we investigate the thermal relaxation of air in the wake of single-filament plasmas using shadowgraphy. We demonstrate that the transient change in refractive index associated with relaxation of the gas can be used to reject both continuous and time-varying spectroscopic signals, including emission from laser-produced plasmas. This method can augment temporal gating of simple optical detectors.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 30, 2021
- Source ID
- 10.1364/ol.430809
Entities
People
- Igor Jovanovic
- John Nees
- Lauren A. Finney
- Milos Burger
- Patrick Skrodzki
- Robert Nawara
Organizations
- Air Force Office of Scientific Research
- Defense Threat Reduction Agency
- National Nuclear Security Administration
- National Science Foundation
- University of Michigan