Patent ID: 6282005
Filing Date: 2001-08-28
Classification: G02F,H04B,H04J

Abstract:
An optical communications system for the transmission and reception of an optically modulated information signal over a communications link, said system comprising:an optical transmitter includinga laser source producing an optical source signal at wavelength .lambda..sub.0, andan external modulator of the SPW type coupled to receive the optical source signal, the SPW modulator having a transfer function with a resonance at .lambda..sub.0 for intensity modulating the optical source signal with an information signal, said SPW modulator comprisinga multilayer waveguide includinga thin SPW generation layer having a thickness designed to support at least one surface plasmon wave mode, anda first dielectric layer located on one side of said SPW generation layer forming a guiding layer of the waveguide and supporting at least one guided mode of said optical source signal into and out of said waveguide; anda modulation structure including,a second dielectric layer located on the other side of the SPW generation layer and formed of electro-optic material whose refractive index may be varied, andmeans disposed on a side of the dielectric layer opposite the SPW layer, for electrically varying the refractive index of said electro-optic material to perturb the propagation constant of said at least one plasmon wave mode in said thin SPW generation layer and thereby the coupling coefficient of the guided optical source signal into the surface plasmon wave;an optical fiber link coupled to said optical transmitter for receiving the optical information signal at a sending end and carrying the optical information signal to a receiving end; andan optical receiver coupled to the receiving end of said optical fiber link for receiving the optical information signal and demodulating the optical information signal into said information signal.