Patent ID: 6025943
Filing Date: 2000-02-15
Classification: H04J

Abstract:
An optical interferometer, comprising:a first branch and a second branch;an optical divider configured to be coupled to a multichannel optical wavelength transmission line and from which the first and second branches diverge;an optical signal superposition means configured to be coupled to a multichannel optical wavelength transmission line and at which the first and second branches converge;a first signal add/drop means in the first branch and a second signal add/drop means in the second branch; andphase difference means in the second branch,wherein:an optical signal transmitted over an optical wavelength channel in wavelength division multiplex fashion can effectively be dropped from the channel and another optical signal can be added to that channel;the optical divider is configured to receive optical signals transmitted in wavelength division multiplex fashion on the plurality of wavelength channels and generate optical signal portions for each of the first and second branches for the optical signal to be dropped;the optical signal superposition means is configured to receive the optical signal portions from the first and second branches and superimpose one on the other; andthe phase difference means is configured to create a phase difference between the optical signal portions so that the optical signal portions constructively interfere with one another when being superpositioned by the optical signal superposition means.