Development of Raman-shifted probe laser beam for plasma diagnosis using polaro-interferometer

Abstract

Optical diagnostics of laser-produced plasma requires a coherent, polarized probe beam synchronized with the pump beam. The probe beam should have energy above the background emission of plasma. Though the second harmonic probe beam satisfies most of the requirements, the plasma emission is larger at the harmonic frequencies of the pump. Hence, at high intensities we need a probe beam at non-harmonic frequencies. We have set up a Raman frequency shifted probe beam using a pressurized hydrogen cell that is pumped by the second harmonic of the Nd glass laser that operates at only one Stokes line of 673.75 nm.

Determination of self generated magnetic field and the plasma density using Cotton Mouton polarimetry with two color probes

“…Two identical, high dynamic range CCD cameras can be used as detectors of probe beams' relative intensity in two orthogonal polarizations at different locations. A practical way of getting the desired probe beams, with suitable properties has been reported earlier [10]. Two probe beams are incident on the target along the target normal as shown in the Figure 1.…”