Plasma electron density diagnosis by Nomarski interferometer with Raman compression cascade system

Nomarski interferometer is an effective measurement to diagnose the electron density of laser-produced plasma. Using Raman compression cascade system with 1 054 nm incident light, a probe beam that has a 308 nm wavelength, 28 ps pulse duration and 1 mJ energy was obtained. The probe beam was applied in the polarization interferometry to measure the electron density of Au plasmas produced by 527 nm main beam at Xingguang-Ⅱ facility. The measured interferograms were analyzed to and a two-dimension profile of electron density was obtained. The result shows that with the aid of the probe beam, the electron density can be probed with a much higher temporal resolution and the disturbance of harmonic can be effectively avoided.