A novel optical modulator system with enhanced linearization properties

The authors propose a novel optical modulator system that has the properties of having a null third-order intermodulation distortion (IMD); a spurious signal free dynamic range in excess of 100 dB as determined by the second-, fourth-, and fifth-order IMD; and a linear dynamic range of 2.46 radians. It is shown that a combination of a tandem of two directional couplers has the property of eliminating completely third-order IMD term, gives a large spurious signal free dynamic range, and provides a simple and practical solution to the problem of linearization of optical modulators. >