Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

FP5

SHARP Résumé de rapport

Project ID: HPRI-CT-2001-50037
Financé au titre de: FP5-HUMAN POTENTIAL
Pays: France

Fast pockels cell optically driven

Acting as LOA sub contractor, Fastlite company was in charge of developing one prototype of ultrafast Pockels cell able to switch an optical gate in less than 200 picoseconds with a contrast ratio better than 10.

Principle:
This cell is composed by 2 RTP crystals inserted in ceramic transmission lines exhibiting a dielectric constant very close to the RTP one. Crystal is surrounded by 2 photo-conductive switches in GaAs (Gallium Arsenide) allowing a very fast commutation.

The principle consists in the discharge of one part of the transmission line (RTP crystal) in the 2 lines surrounding this crystal. The switching time is very fast (<1ps) and generate a negative pulse with an amplitude half than the load voltage applied on both photo-conductive switch. These 2 pulses propagate in the transmission line at a speed c/Õr (about 12 107m/s).

The size of RTP crystals is 6 x 6 x 7mm. So the propagation time through the crystals is about 50ps.

The switching time of the Pockels cell is also linked to the light velocity in the crystal (40ps).

Reported by

Laboratoire d'Optique Appliquée
Batterie de l'Yvette
91761 Palaiseau
France
See on map