Design of micro resonator quantum well intensity modulator

A compact rectangular resonator quantum well intensity modulator for operation in the wavelength band around 1 μm is described. The modulator is realized using InGaAs/GaAs modulation-doped quantum wells and operates on the principles of index change caused by blue shifts of the absorption edge. High efficiency 90° bends are used to form the resonator and to provide optimal coupling to the external waveguide. The benefits are to reduce loss, to relax the lithography requirements and to provide more flexible contact designs to the modulator. The characteristics of the modulator are analyzed using MATLAB and FDTD simulation tools with refractive index profiles based on measured absorption parameters. A model including parasitics is developed for HSPICE transient simulations and is run in the AGILENT ADS environment. The performance parameters are determined to be an extinction ratio of 10.4 dB, a bandwidth of 33 GHz, and a dc power less than 1 mW for device dimensions of 16 × 6 μm 2 .