Observation Of Near Total Polarization In The Ultrafast Laser Ablation Of Si

摘要

We report nearly completely polarized emission from the plasma produced in the femtosecond ablation of Si(111). Pairs of ultrashort laser pulses were focused onto the target in air, and the polarization spectrum was measured as a function of energy, pulse delay, and polarization state of the laser. When the laser was focused on the surface, the fluorescence continuum was strongly polarized, whereas discrete lines appeared as minima in the polarization spectrum. Under this focusing condition, the continuum polarization increased with pulse delay and decreased with pulse energy and fluorescence wavelength, with ＞95% polarization in the ultraviolet.