Design of a spectrum-expanded polymer Mach–Zehnder interferometer electro-optic switch using two-phase generating couplers

Abstract

A novel structure, thorough analysis and design technique are presented for a kind of polymer Mach–Zehnder Interferometer (MZI) electro-optic (EO) switch consisting of two-phase generating couplers (PGCs). By optimizing the PGCs structure, the output spectrum of the two PGCs based MZI EO switch is greatly expanded to almost six times of that of the traditional MZI EO switch with two 3 dB directional couplers. Under a central wavelength of 1550 nm, the driving voltages of the designed switch are as low as about 0 (ON state) and ±0.925 V (OFF state) with an EO region length of 5000 μm. A wide spectrum more than 350 nm (1380∼1730 nm) is achieved, and within this wavelength range, the crosstalk is less than −30 dB, and the insertion loss is less than 5.91 dB which is larger than that of the traditional MZI EO switch due to the longer waveguide length by introducing two PGCs. The design technique on the two PGCs based MZI EO switch is supported to be reasonable compared with the beam propagation method (BPM). The proposed structure shows potential wide applications especially in optical cross-connect (OXC) and optical add-drop multiplexing (OADM) systems.