Chinese Acad Sci, Inst Phys, Lab Opt Phys, Beijing 100080, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
By observing the fundamental and second harmonic emission from a plasma produced by a. 150 fs, 5 mJ laser at 800 nm, the electron temperature, the expansion speed and the scalelength of the plasma. have been diagnosed. Moreover the polarization of the fundamental and second harmonic emission has been studied. Tl,is could be it useful diagnostic for modulation at the critical surface of the plasma.