Photovoltaically powered modulating retroreflector optical data links

The development of a photovoltaically (PV) powered, laser communication system that constitutes a miniature, highly energy-efficient wireless communication technology is described. The technology is based on the direct integration of a multi-quantum well (MQW) modulating retroreflector (MRR) optical communication node and a monolithically integrated module (MIM) PV power source. The MQW MRR optical data link exploits the shift in the MQW absorption peak under an applied reverse bias to modulate incident laser light enabling binary encoding of data for transfer. A MIM consists of many individual solar cells monolithically integrated on a single substrate and offers the design versatility necessary to allow efficient electrical conversion of both incident sunlight and the system laser-light and the ability to match the voltage output to the MRR requirements. A description of the development of the MRR and MIM components of the system along with the power management and distribution circuitry is given. Results of bench-top demonstrations of the operational system are presented.