近年來砷化銦鎵/磷化銦單光子雪崩型偵測器被廣為研究，此種偵測器可吸收近紅外光，因此可用於以光纖通訊為基礎的量子通訊與量子電腦；然而，此材料系統在磊晶時容易產生缺陷，因此相較於矽製程的單光子雪崩型偵測器，會有較高的暗計數與二次崩潰效應，使得許多應用會受限於暗計數而無法達到弱光且長距離的偵測，本論文將比較正弦波閘控模式與傳統脈衝閘控模式，並將元件降溫以研究暗計數在兩種操作模式下的特性表現，以期作為各應用中單光子偵測器的操作準則。 在本論文中我們以正弦波閘控模式操作元件，因其相較於傳統的脈衝閘控模式操作，能有效降低電容耦合訊號來減少錯誤訊號且可降低辨別位準；實驗中我們比較此兩種操作模式的暗計數在不同溫度下、不同頻率下以及不同交流偏壓振幅下的特性表現。首先將操作頻率固定(1MHz)後改變溫度，發現元件以正弦波閘控模式操作的暗計數在所有溫度範圍皆不比脈衝閘控模式的操作來的好；然而，當我們進行變頻率截取暗計數的實驗卻發現正弦波閘控模式操作在高頻下擁有較好的暗計數表現，此歸諸於越高頻的情況下閘控寬度越短。我們更進一步在固定的超額偏壓下，利用調變交流偏壓振幅以改變閘控寬度，當交流偏壓振幅越大，閘控寬度越小，實驗結果發現當溫度介於100K至200K之間可有效利用調變交流偏壓振幅來改善暗計數，於200K時暗計數機率更是低於10-4 %。 ;In recent years, InGaAs/InP single photon avalanche diodes (SPADs) have been widely studied. The detectors are capable of detecting near infrared light, therefore they are commonly used for the applications based on optical fiber links such as quantum communication and quantum computation. The III-V based SPADs have higher dark count as compared to the Si-based SPAD because III-V materials is prone to defects in epitaxy, which restricts the practical applications of low-light level and long range detection. In this thesis, we compare the dark count characteristics of SPAD under two different operation modes of the sinusoidal wave gated mode and the pulsed gated mode, anticipating that our investigation could provide an operation guideline for SPAD-based applications. In this work, we operate the SPAD using sinusoidal wave gated mode for that it could effectively circumvent the capacitive signals and hence reduce the false counts as well as lower the discrimination level as compared to the SPAD using pulsed gated mode. In experiment, the dark count rates are compared for two different gated modes under various conditions, including temperature, operating frequency, and peak-to-peak amplitude of sinusoidal wave. We find that the dark count rate for pulsed gated mode performs better than that for sinusoidal wave gated mode at the whole temperature range. However, while the operating frequency is varied, the DCP shows distinct behavior for such two operation modes. The DCP for SPAD under sinusoidal wave gating performs better at high operating frequency, which is attributed to the smaller effective gate window at higher frequency. Based on this concept, we tend to tune the effective gate window by varying the peak-to-peak amplitude of sinusoidal wave. Our results show the DCP can be effectively improved by increasing the peak-to-peak amplitude of sinusoidal wave at the temperature range of 100 K to 200 K. It is worthy to especially point out that the dark count probability per gate is suppressed to lower than 10-4 % at the temperature of 200K.
