High-contrast reflection modulation at normal incidence in asymmetric multiple quantum well Fabry-Perot structure

The authors have modelled the properties of a multiple quantum well pin diode optical modulator with the natural semiconductor reflectivity (R approximately=0.3) at its front surface and a high reflector (R approximately=0.95), such as an integrated semiconductor quarter-wave stack, at the back. By using resonant electroabsorption, rather than electrorefraction, the calculations show that it is possible to achieve contrast ratios of over 200, with less than 3 dB insertion loss.