title: Doppler velocimetry in a supersonic jet by use of frequency-modulated filtered light scattering.
abstract: A new nonintrusive velocimetry diagnostic that combines the sensitivity of frequency-modulated (FM) absorption spectroscopy techniques and the spectral discrimination afforded by atomic-vapor absorption filters is presented. Doppler-shifted light from a FM Ti:sapphire laser scattered from a supersonic flow is imaged through a potassium-vapor cell and is detected by FM spectroscopy. The difference between the potassium resonance frequency and the laser frequency when the scattered light is in resonance is the flow-induced Doppler shift.
authors.forename: J H
authors.initials: JH
authors.lastname: Grinstead
authors.forename: N D
authors.initials: ND
authors.lastname: Finkelstein
authors.forename: W R
authors.initials: WR
authors.lastname: Lempert