Analysis of the radiation backscattered from a laserhyphen;produced plasma

摘要

The light backscattered from a plasma produced by focusing a 1hyphen;GWQhyphen;switched ruby laser has been measured. The reflection coefficient of the plasma is of the order of 1ndash;2percnt; and the reflected energy increases with the incident energy. The backscattered light is Doppler shifted; the shift is not uniform but varies markedly along the focal spot indicating a concave reflecting layer penetrating into the target with velocities of (2ndash;4) times;106cm/sec. The second harmonic of the ruby laser is also present in the backscattered light.