Mach-Zehnder Interferometer Electro-optic Switch Research Articles

Investigation on an ultra-compact Mach–Zehnder interferometer electro-optic switch using poled-polymer/silicon slot waveguide

By using poled-polymer/silicon slot waveguides in the active region and employing the Pockels effect of the poled-polymer, we propose a kind of Mach–Zehnder interferometer (MZI) electro-optic (EO) switch operated at 1550 nm. Dependencies of switching characteristics versus the slot waveguide parameters are investigated, including EO overlap integral, power ratio confined in the slot, and voltage-length product. Given the dimension of the silicon strip of 190 × 300 nm, as the slot width varies within 50–100 nm, the switching voltage can be as low as 1.0 V with only 0.17–0.35 mm active region length, and the whole device length is only about 770–950 μm. For the switch with 50 nm slot width, the insertion loss is about 4.42 dB under both operation states, and the crosstalk under cross-state and that under bar-state are about −48.2 and −65.3 dB, respectively. An impressive advantage of this switching structure lies that the voltage-length product (0.17–0.35 V mm) is at least 19–40 times smaller than that of the traditional polymer MZI EO switch (6.69 V mm). Compared with our previously reported two kinds of MZI or microring resonator assisted MZI EO switches, this switch does exhibit some superior characteristics, including low switching voltage, compact device size and small wavelength dependency, due to the use of slot waveguides in the MZI EO region.

A Mach-Zehnder interferometer electro-optic switch with ultralow voltage-length product using poled-polymer/silicon slot waveguide

By using poled-polymer/silicon slot waveguides in the active region and the Pockels effect of the poled-polymer, we propose a kind of Mach-Zehnder interferometer (MZI) electro-optic (EO) switch operated at 1 550 nm. Structural parameters are optimized for realizing normal switching function. Dependencies of switching characteristics on the slot waveguide parameters are investigated. For the silicon strip with dimension of 170 nm×300 nm, as the slot width varies from 50 nm to 100 nm, the switching voltage can be as low as 1.0 V with active region length of only 0.17–0.35 mm, and the length of the whole device is only about 770–950 μm. The voltage-length product of this switching structure is only 0.17–0.35 V·mm, and it is at least 19–40 times smaller than that of the traditional polymer MZI EO switch, which is 6.69 V·mm. Compared with our previously reported MZI EO switches, this switch exhibits some superior characteristics, including low switching voltage, compact device size and small wavelength dependency.

Polymeric Multimode Interference Mach–Zehnder Interferometer Electro-Optic Switch Using Embedded Coplanar Waveguide Electrode: Theory, Design, and Analysis

The self-imaging theory is improved for designing a polymer multimode interference Mach–Zehnder interferometer electro-optic switch. The electro-optic overlap factor is enhanced from 0.6510 to 0.9658 through adopting an embedded coplanar waveguide electrode. Considering the mode dispersion effect, formulations of time-domain response are derived, and switching characteristics are analyzed. The total device length is about 7.175 mm, the switching voltage is 2.622 V, and the switching time is 29.90 ps. The lightwave 3-dB bandwidth is 20 nm, the insertion loss is less than 2.70 dB, and the crosstalk under cross and bar states are less than −55 dB and −45 dB, respectively.

Nanosecond Bias-Free Mach–Zehnder Electro-Optic Switch Based on Dye-Doped Polymer DR1/SU-8 and Microstrip Line Electrode

A bias-free Mach–Zehnder interferometer electro-optic switch is demonstrated with a dye-doped polymer Disperse Red 1 (Tokyo Chemical Industry, Co., LTD, Tokyo, Japan)/SU-8 (MicroChem Corp., Newton, Massachusetts, USA) and microstrip line electrode. The device is carefully designed and optimized for bias-free function and high-speed switching using the three-dimensional beam-propagation method and extended point-matching method, and the switch is seriously fabricated by a wet-etching technique and inductively coupled plasma etching technique for good control of dimension parameters. The measured rise time and fall time at 1,550 nm are both at the level of ~10 ns. Owing to the bias-free function and nanosecond response speed, this switch exhibits potential applications of high-speed optical routing and exchanging.

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

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.