COHERENT CONTROL OF QUANTUM-WELL EXCITONS IN A RESONANT SEMICONDUCTORMICROCAVITY FOR HIGH-SPEED ALL-OPTICAL SWITCHING

Coherent control of excitons in quantum wells embedded in a resonant p lanar semiconductor microcavity versus in quantum wells without the ca vity at high repetition rates is investigated theoretically to determi ne the practical constraints for application in high bit-rate optical switching, It is shown that pi-shifted pulse pairs are optimal to cohe rently populate and depopulate the QW on the 100-fs timescale, For the cavity-free case, the small optical nonlinearity will require devices incorporating similar to 100 quantum wells; the resonant enhancement of the confined mode for the case of the cavity leads to an effective increase in the optical nonlinearity and thus a reduction of the requi red number of quantum wells to similar to 10. In addition, switch arch itectures that avoid interferometers, and thus will have superior temp erature and mechanical stability, based on the microcavity are propose d, We believe that although room-temperature operation of a 100-Gb/s s witch based on this principle may be difficult, operation at liquid-ni trogen temperature should be feasible.