Abstract

Coherent anti-Stokes Raman spectroscopy (CARS) has been used to make precise measurements of temperature, pressure, and velocity throughout the isentropic expansion and across the normal shock of a supersonic methane jet. The experimental apparatus consists of a 4-W single-mode 5145-Å argon-ion laser and a 100-mW single-mode tunable dye laser, both of which are focused to a 5-μm diam spot in the methane jet. The anti-Stokes signal generated in the jet defines a volume ~5 μm in diameter and 200 μm long.

© 1981 Optical Society of America