ELECTROOPTIC APPARATUS FOR THE MEASUREMENT OF ULTRASHORT ELECTRICAL SIGNALS

摘要

An electrooptic measuring apparatus having both high voltagesensitivity and femtosecond time resolution comprises coplanar transmission linefabricated on a semi-insulating multiple quantum well structure. An electricalsignal, such as from a high speed electrooptic device, injected onto the transmissionlines creates an electrical field parallel to the layer planes of the multiple quantumwell structure. Excitonic electroabsorption by the multiple quantum well structure,in response to the parallel field, changes the transmissivity of the multiple quantumwell structure. An external light beam directed through the multiple quantum wellstructure is modulated by the changes in transmissivity. By detecting thismodulation, a sampling of the electrical signal is achieved.