Simulation of the generation of ultrafast midinfrared laser pulses

A numerical simulation of an ultrafast semiconductor switch for 10.6 mu m CO/sub 2/ radiation is presented. It is based on the solution of the Helmholtz electromagnetic wave equation for p-polarized light and the ambipolar diffusion equation. Calculations are performed in various time dependent inhomogeneous plasma profiles. The analysis shows that the temporal reflectivity depends on the initial visible radiation fluence, duration, and diffusion coefficient of the sample. The results support the feasibility of generating midinfrared ultrashort pulses between 100 fs and 65 ps. By proper choice of the laser fluence and the semiconductor material, longer pulses are also possible.<
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