Patent ID: 7515778

Claim:
An external modulator for an optical input source, creating a modulated optical output signal with a dynamically adjustable extinction ratio, the external modulator comprising an input waveguiding section for receiving a continuous wave (CW) optical input signal; an input optical splitter, coupled to the output of the input waveguiding section for dividing the CW optical input signal into a pair of CW optical input signals; a pair of optical waveguides coupled to the outputs of the input optical splitter, the pair of optical waveguides forming a pair of modulator arms for supporting the propagation of the optical signal, each modulator arm partitioned into a plurality of N waveguide modulator segments with a separate isolation region disposed between adjacent waveguide modulator segments; a plurality of modulator electrodes disposed adjacent to each waveguide modulator segment of the plurality of N waveguide modulator segments in a one-to-one relationship; a plurality of N separate electrical drive signal sources, each source coupled through modulator electrodes to a separate waveguide modulator segment of the plurality of N waveguide modulator segments, each drive signal source separately energized/de-energized to control the phase shift present between the optical signals propagating along each arm of the pair of modulator arms so as to dynamically adjust the extinction ratio, providing at the output of the pair of modulator arms a pair of modulated optical signals; an output optical combiner for combining the pair of modulated optical signals into a modulated optical output signal; and an output waveguiding section coupled to the output of the output optical combiner for supporting the propagation of the modulated optical output signal.