Abstract

Acousto-Optical Switch Modules for Vector-Matrix Crossconnect Architectures

J.Sapriel (CNRS-LPN, Marcoussis, France); S.Gosselin (France Telecom R&D, Lannion, France)

e-mail: jacques.sapriel@lpn.cnrs.fr

An acousto-optic based vector-matrix switching architecture is proposed for a WDM Telecom- munication crossconnect. Each module can be used to implement a 8x8 point-to-point crossbar switch and carry a specific photon wavelength in a WDM system. Input and output ports are arranged in linear arrays of 8 single modes fibers. Light from each input port is collimated along the system axis by a microlens and impinges at Bragg incidence on one of the channels of a multichannel acousto-optical cell. The 8 piezoelectric transducers of the multichannel deflector control independently the 8 corresponding optical beams. To access a given output port, a RF signal is tuned to provide the proper deflection angle. Light reachs the output port after passing successively through a Fourier lens and a second multichannel deflector oriented perpendicular to the first one. The best choice for the acousto-optic material in the multichannel commutators is Gallium Arsenide crystals. Experiments are presented for longitudinal and transverse waves in this material at 1.55m and 1.3m. It is shown that the module is insensitive to light polarisation in all cases according to Telecommunication requirements.

Section : 9