Abstract

The emission of ultrafast THz pulses after femtosecond laser pumping was recently introduced by Zhang and Auston [1] as a sensitive probe of the semiconductor surface region. Photoexcited carriers created near the surface are accelerated by the electric field present due to band-bending. The resulting photo current radiates an electro-magnetic pulse posessing frequency components in the THz-regime. The detailed structure of the THz pulse carries information about the built-in surface fields in the sample.

© 1994 Optical Society of America