Design of multiple-quantum-well electroabsorption surface-normal modulators using asymmetric fabry-perot structures

We presented a systematic approach for optimizing the performance of a multiple-quantum-well eleectroabsorption surface-normal modulator using asymmetric Fabry-Perot structures.The primary requirements of these modulators are low drive voltage,high contrast ratio(CR), low insertion loss,and high speed.For specified high CR(> 20dB) requirement, maximizing /spl Delta//spl alpha//sub max///spl Delta/ of the material structure,where /spl Delta//spl alpha//sub max/ is the maximum absorption change and /spl Delta/F is the corresponding applied electric field, or adopting R/sub T/ /spl tilde/ 60% of asymmetric Fabry-Perot etalon can obtain low-drive voltage modulator. There are trade-off between the requirements of low-drive-voltage and high frequency-response.The criterion of the optimization is to maximum /spl Delta//spl alpha//spl Delta/F/sup 2/. Our theoretical model shows that wider wells give large /spl Delta//spl alpha//sub max///spl Delta/F/sup 2/ for ASFP modulators.