Electrical signals are measured (analyzed and displayed) with subpicosecond resolution by electro-optic sampling of the signal in an electro-optic crystal, the index of which changes in response to the electric field produced by the signal, in accordance with the Pockels effect. The crystal is disposed...http://www.google.de/patents/US4603293?utm_source=gb-gplus-sharePatent US4603293 - Measurement of electrical signals with subpicosecond resolution
