Polarization independent InGaAs/lnP chopped quantum well interferometric space switch at 1.55 mum

A Mach-Zehnder Interferometric (MZI) space switch using a novel CRE grown InGaAs/InP chopped quantum well (CQW) phase section is presented. Each CQW consists of three 3IA. InGaAs strained quantum wells separated by 12A InP barriers. This structure shows a shift of the absorption edge as high as 80nm at lOV reverse bias. The heavy hole and light hole subbands cross at approximately 0.6% tensile strain. Using these chopped quantum wells, we realized MZ/'s with low attenuation and a V2.l product as low as 3.6 V2.cm. Finally, we realized full polarisation independent switching using 0.75% tensile strained CQW's

Low-crosstalk penalty MZI space switch with a 0.64-mm phase shifter using quantum-well electrorefraction

We investigate Mach-Zehnder interferometric (MZI) space switches with quantum-well phase shifters. We find that the minimum phase shifter length is limited by additional crosstalk due to electroabsorption-induced imbalance in the MZI. This criterion also provides an optimal detuning between the bandgap and the operating wavelength of the MZI. Finally, we present a novel MZI with an ultrashort 0.64-mm phase shifte

Electrorefraction in strained InGaAs/InP chopped quantum wells : significance of the interface layers

We present a model for electrorefraction based on the quantum confined Stark effect (QCSE) in strained InGaAs/InP chopped quantum wells (CQWs) consisting of three 27 Å InGaAs wells separated by 15 Å InP barriers. The model fully takes into account the influence of the thin interface layers around each well. We experimentally verify the model on a InGaAs/InP CQW which combines a large 60 meV QCSE redshift at 11.7 V bias with waveguide transparency at 1.55 µm, which is two times larger than in a InGaAsP quaternary well. The calculated electroabsorption spectra of the CQWs are in good agreement with experiment. We finally applied the Kramers–Kronig transformations for calculating the switching voltage in a Mach–Zehnder switch employing CQWs in the phase shifting section. The model was found to be in good agreement with experiment for both polarizations