Abstract

In large scale optical computing systems using CO₂ laser radiation the fast modulation of an optical power at 13-15-µm wavelength by an optical signal at 10-µm wavelength is necessary for getting off chip and transferring to fiber results of the computation. For the first time we calculate the limit on data coding rate for the new InGaAs multiple quantum well (MWQ) modulator, proposed by us recently.¹ The idea was to control the optical transparency of a MQW heterostructure by modulating the effective temperature Te of free carriers in the QWs. In the scheme discussed below (Fig. 1), the electron gas heating is effected by a resonant intersubband absorption of CO₂ laser radiation (ISB light). Modulating the ISB radiation power at a high speed, we can effectively control T_e and hence the QW transparency at the fundamental absorption wavelength l3-15 µm (IB light).

© 1993 Optical Society of America