| 摘要: | 立基於我們過去以及持續的努力與成果，我們致力於開發出一砷化銦鎵單光子雪崩偵測器，預期能具備高速操作、高訊雜比、高時間解析度的極佳特性，並可望成為最適合應用於量子通訊、量子計算以及真亂數產生器的單光子感測元件。在元件層面，針對元件的吸收層與累增層作特殊結構設計，以改善暗計數、光偵測效率以及時間解析度。在製程方面，我們也會採用多道平台方式以避免邊緣崩潰並對側壁作特殊保護與處理以降低表面態位密度對暗計數的影響。除了開發傳統採正回饋機制形成大量崩潰載子的單光子雪崩偵測器外，我們亦著力於開發採負回饋機制的自我調節單光子雪崩偵測器，以簡化截止電路並降低二次崩潰效應。在電路層面，為了提高操作速度，我們將同時運用自差分電路以及弦波閘壓電路以達成極低訊號位準之辨別，旨在降低二次崩潰效應以及期能實現光子數目解析之功能；最後，為提高單光子感測器的最高計數率且更進一步提高光子數目解析準確度，我們將單一元件層面提升到陣列層面，並且以光子統計方法實現一真正的隨機亂數產生器，這將對量子技術的發展有一大助力。 ;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. |
