Crosstalk Reduced Digital Optical Switch with Single Electrode Designed for InP

Coherent crosstalk of optical space switch matrices is a key problem of optical transparent networks. A new crosstalk compensating technique based on the integration of a single electrode mode converter as correcting device into a 1×2 or 2×2 digital optical switch (DOS) is proposed and theoretically investigated. Introduction of the mode converter stage enhances a −20 dB crosstalk DOS device to−40 dB with only a small increase of the device length. The new scheme with one common electrode for DOS and converter simplifies a recently published architecture needing 4 additional electrodes and a special control algorithm. A realistic design of a−40 dB crosstalk DOS based on InP is presented.