T-junction resonant modulators and detectors in CMOS

Abstract

Design of optical modulators and detectors is investigated. A new design idea is proposed for optical modulators - T-junction. The T-junction allows to decouple the Extinction Ratio from the Bandwidth and to optimize each separately. Initial T-junction modulator provides an increase in bandwidth - 13 GHz versus 3 GHz, for the previous designs. An analytical model is created and is verified against the experimental data of the T-junctions. The model is then used to optimize the modulators and to achieve a design operating at above 35 GHz. The bandwidth increase with optical intensity is investigated in detectors. The unusual behavior is reproduced in Sentaurus. The severe depletion of the N and P regions is found to be responsible for the bandwidth variations. Increasing the doping of the P and N regions proves to successfully tackle the problem.