Dual wavelength interferometry for gases and plasmas diagnostics

A. Morozov¹ and A. Dogariu<sup>1,2

1</sup>Department of Mechanical and Aerospace Engineering, Princeton University

²Aerospace Engineering Department, Texas A&M University



We have developed a two color-interferometry diagnostics for gases and plasmas technique using dual tunable probe laser pulses provided from a single femtosecond laser system equipped with an optical parametric amplifier (OPA). Simultaneous measurements of phase change using two wavelengths can allow to separate the contributions to the refractive index from free and bound electrons of heavy particles (atoms, ions and molecules). The technique has great potential for measurements of individual species in plasmas, as well as a diagnostic with high spatial and temporal resolution for imaging of shocks and boundary layers in supersonic gas flows, flames, and laser or HV electrical discharge induced plasmas. We will present dual interferometry measurements in gas flows, and in shocks created in gases.