Nanosecond modulation of thermal emission

摘要

Femtosecond laser pulses are used to modulate the thermal emission from semiconductor materials at the nanosecond timescale.A visible-frequency laser photoexcites energetic free carriers in intrinsic Si and GaAs wafers.As these free carriers return to equilibrium,they not only emit thermal radiation on a picosecond time scale but also modulate the semiconductor thermal emission on a nanosecond to microsecond time scale,offering a novel route towards ultrafast infrared optical pulses.