Patent ID: 6229632
Filing Date: 2001-05-08
Classification: H04B

Abstract:
An optical transmission system, comprising:a first laser emitting a light at wavelength W1;a second laser emitting a light at wavelength W2, different than wavelength W1;a first coupler having a first input port receiving said light at wavelength W1, a second input port receiving said light at wavelength W2, and an output port transmitting a combined light at wavelength W1 and wavelength W2;a modulator responding to an applied electrical stimulus, having an input port coupled to said first coupler output port and receiving said combined light, a first modulator output port providing a combined light which is modulated in phase with said electrical stimulus, and a second modulator output port providing a combined light which is modulated in phase opposition to said electrical stimulus;a first optical filter having an input port coupled to said first modulator output port, and an output port transmitting modulated light at wavelength W1;a second optical filter having an input port coupled to said second modulator output port, and an output port transmitting modulated light at wavelength W2;an optical combiner having a first input port coupled to said first optical filter output port, a second input port coupled to said second optical filter output port, and an output port transmitting a combined modulated light at wavelength W1 and wavelength W2;a first apparatus having an input port coupled to said output port of said optical combiner, a first output port transmitting modulated light at wavelength W1, and a second output port transmitting modulated light at wavelength W2;a first detector having an input port coupled to said first output port of said first apparatus, and having an output port providing a first electrical output signal;a second detector having an input port coupled to said second output port of said first apparatus, and having an output port providing a second electrical output signal; anda second apparatus having a first input port coupled to said output port of said first detector, a second input port coupled to said output port of said second detector, and an output port providing the difference between said first electrical output signal and said second electrical output signal.