Dynamic band unblocking and leakage two-photon absorption in InSb
نویسندگان
چکیده
An experimental demonstration of a dynamic decrease of the optical band gap of bulk n-InSb induced by picosecond, midinfrared laser pulses is reported. This occurs as a result of laser heating of the quiescent electron distribution by free-carrier absorption. The hot electrons vacate low-energy states near the conductionband minimum, unblocking terminal states for two-photon absorption across the band gap. This ‘‘leakage’’ two-photon absorption is detected as a consequence of changes to the refractive index and absorption coefficient of the semiconductor caused by photocarriers. The onset of dynamic band unblocking agrees with a calculation of laser-induced electron heating. @S0163-1829~97!03836-8#
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