MULTIMEDIA ALZHEIMER'S EDUCATION IN ASSISTED LIVING

Not Available A novel photoreceiver is proposed based upon the high optical sensitivity, gain and impedance transformation properties of an optoelectronic thyristor and HFET integrated circuit. As part of a monolithic optoelectronic technology, the thyristor is implemented as a vertical cavity device and is compatible with complementary HFET digital and analog electronics, with a complementary bipolar analog/digital gate configuration, and with vertical cavity lasers. The thyristor is based upon strained quantum well GaAs epitaxial growth with a natural emission frequency of 1 um. It is designed as a resonant vertical cavity detector with a three quantum well active absorbing region of about 300A and with current blocking barriers on either side resulting in detection which is highly resistant to radiation. With the absence of natural oxides in this structure, the HFET electronics is also radiation tolerant and implements high performance complementary logic because the natural threshold (+0.3V) are positive providing ample noise margins. The thyristor is unique in that it performs digital/analog detection in the off state and produces laser emission in the on state. By integrating with CHFET logic, a smart pixel may be designed to perform the functions of an emitter, modulator or detector depending on the logic levels applied to the resonant cavity device. In the integrated form, BER's of <10(sup -10) are expected based upon the dark current levels obtained in these devices. In thi