Electro-optic detection of femtosecond electromagnetic pulses by use of poled polymers

We report the generation and coherent detection of freely propagating ultrashort baseband electromagnetic pulses. Using optical rectification in (110) GaAs for wideband emission and electro-optic sampling in a poled polymer for wideband detection, we demonstrate spectral sensitivity that extends from the far infrared (lambda similar to 100 mum) to similar to33 THz (lambda = 9 mum). Over a band of nearly 20 THz, a relatively flat frequency response is observed. We discuss issues that limit the response bandwidth. (C) 2002 Optical Society of America.