Temperature dependence of femtosecond electromagnetic radiation from semiconductor surfaces

We present observation of temperature dependence of optically induced femtosecond electromagnetic radiation from several semiconductors. When the sample temperature decreases from 280 to 80 K, over 4 times and 21 times increases of the radiated peak field and radiated energy have been found. A large shift of the frequency spectrum of the radiation was observed when the InSb sample temperature was tuned over this range.