Optoelectronic integrated tristable device with optically controlled set and reset functions

摘要

An optical tristable device with optically controlled set and reset functions is developed for the first time. The device structure is a vertical and direct integration of four heterojunction phototransistors and a laser diode. Two HPTs (HPT-A and HPT-B) which are integrated just above the LD stripe are utilized to achieve the set operation, where the internal optical feedback from the LD to the HPTs takes an important role in the operation. On the other hand, an HPT (HPT-C or HPT-D) integrated slightly away from the position for the set operation is used to achieve the reset operation. The optical feedback from the LD to the HPT-A and the HPT-B is suppressed by the current bypass through the HPT-C connected to both ends of the LD.