Burst-mode femtosecond laser electronic excitation tagging for kHz–MHz seedless velocimetry
Abstract
Burst-mode femtosecond laser electronic excitation tagging (FLEET) of nitrogen is introduced for tracking the velocity field in high-speed flows at kilohertz–megahertz (kHz–MHz) repetition rates without the use of added tracers. A custom-built Nd:glass femtosecond laser is used to produce 500 pulses per burst with pulses having a temporal separation as short as 1 µs, an energy of 120 µJ, and a duration of 274 fs. This enables 2 orders of magnitude higher measurement bandwidth over conventional kHz-rate FLEET velocimetry. Characteristics of the optical system are described, along with a demonstration of time-resolved velocity measurements with ∼ 0.5 % precision in a supersonic slot jet.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 08, 2020
- Source ID
- 10.1364/ol.380109
Entities
People
- Jordan Fisher
- Michael E Smyser
- Mikhail N Slipchenko
- Sukesh Roy
- Terrence R Meyer
Organizations
- Air Force Research Laboratory