0.2 V Drive Voltage Substrate Removed Electro-Optic Mach–Zehnder Modulators With MQW Cores at 1.55 μm

Novel electro-optic modulators in compound semiconductor epilayers using substrate removal techniques are reported. Epilayer consists of a p-i-n junction in which i layer is composed of an InGaAlAs/InAlAs MQW. This creates an optical mode with very strong vertical confinement and overlapping very well with the large electric field of the reverse biased p-i-n junction. This approach combined with the large quadratic electro-optic coefficient due to MQW improves efficiency of modulation significantly. Mach-Zehnder electro-optic modulators fabricated using this approach has 0.2 V (0.6 V) V
_π
for 3 (1) mm long electrodes at 1.55 μm under push pull drive corresponding to record modulation efficiency of 0.06 V·cm.