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
