Development of Ingaas Single Photon Avalanche Diode for Quantum Technology

Based on our previous and continued effort, we aim to develop InGaAs-based single photon avalanche diodes (SPAD) with striking performance of high frequency operation, low-noise, extremely low timing jitter that are the most suitable candidates for the applications of quantum communication, quantum computing, and quantum random number generator. In the device level, by delicately designing each layer structures of devices, such as making modification on the absorption layer and multiplication layer, we can attain the improved dark count rate, photon detection efficiency, and jitter performance. We will also pay careful efforts to the device fabrication, such as applying the multiple mesas for avoiding the premature edge breakdown and the special sidewall treatment for reducing the surface state density. Besides the development of the SPAD exploiting the nature of avalanche effect with positive feedback mechanism, we will also focus on the development of negative feedback avalanche diode (NFAD) that exploits the negative feedback mechanism. In the circuit level, for boosting the operation frequency, we will adopt both the gated-mode SPAD with self-differencing method and sine-wave gating mode with band reject filter for achieving an almost noise-free output signal. Furthermore, we shall extend the single SPAD device to an SPAD array. The SPAD arrays with framed readout mode have enabled very high-performance flash LADAR systems and that with asynchronous readout mode will enable high rate quantum key distribution and other quantum communications. For the final system level, we should develop and program an algorithm for FPGA to provide the control to the SPAD array and sets read-out rate and reads the counter values. We aim to carry out a NFAD array for photon number resolving (PNR). As a first stage to examine the functionality of NFAD array, we focus on implementing the quantum random number generator (QRNG) by exploiting the PNR ability of NFAD array. Due to both the improvement of device performance and the integration of readout circuits, our work could be a driving force for the applications of quantum technology that requires a multi-pixel near-infrared single-photon detection.