The influence of electronhyphen;hole density profile on the picosecond timehyphen;resolved reflectivity measurement in silicon

摘要

The influence of the spatial distribution of electronhyphen;hole plasma on reflectivity measurement is studied in this paper. The plasma density deduced from the reflectivity measurement represents the surface density satisfactorily, if the pump penetration depth is not too short compared with probe wavelength. Besides, when plasma resonance does not take place, the probe incident angle should not be close to Brewsterrsquo;s angle lsqb;see, for example, M. Born and E. Wolf,PrinciplesofOptics, 6th ed. (Pergamon, New York, 1980), p. 43rsqb; for exponentialhyphen;like plasma density distribution; otherwise, when the phasma resonance takes place, strong nonlinear recombination and diffusion should be present. In other cases, a general applicable method for data processing is suggested.