ALL-OPTICAL ASYMMETRIC FABRY-PEROT REFLECTION MODULATORS

Abstract

Operating conditions of all-optical asymmetric Fabry-Perot modulators are discussed based on the experimental results of two modulators with different nonlinear spacers of GaAlInAs/AlInAs and strained-layer InGaAs/GaAs multi-quantum wells. These modulators operate at wavelengths of 1.3 and 0.92 µm, and offer an on/off contrast ratio of greater than 1000:1. An “on” state with an insertion loss of 2.2 dB existed for pump intensities of 30 kW/cm 2 and 3 kW/cm 2, respectively. The corresponding carrier densities for these pump intensities are approximately the same, at 4×1017 cm –3. The switching pump beam intensity of the modulator and its response time are analyzed in terms of saturation carrier density and carrier lifetime of the nonlinear spacer material. Requirements for the nonlinear spacer material and device parameters are discussed for low power and fast modulators.