We have generated electromagnetic beams from a variety of semiconductors. When a bare semiconductor wafer was illuminated by femtosecond optical pulses, electromagnetic waves radiate from the surface and form collinear diffraction-limited electromagnetic beams in the inward and outward directions. The amplitude and phase of the radiated field depend on carrier mobility, the strength and polarity of the static internal field at the semiconductor surface.

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.