A bio-inspired single photon detector with suppressed noise and low jitter

Abstract

A novel short wave infrared single photon detector was conceived for wavelengths beyond 1 μm. The detector, called the nano-injection photon detector, is conceptually designed with biological inspirations taken from the eye. Based on a detection process similar to the human visual system, the detector couples a nano-scale sensory region with a large absorption volume to provide a low-noise internal amplification mechanism, high signal-to-noise ratio and quantum efficiency. Tens of thousands of devices were fabricated in different configurations with conventional processing methods in more than 20 iterations. For low speed imaging applications, the detectors have shown gain values reaching 10,000 with bias voltages around 1 V. Ultra-low noise levels were measured at gain values exceeding 4,000 at room temperature: Fano factors as low as 0.55 has been achieved, which indicated a statistically stable amplification mechanism and resulting sub-Poissionian shot noise. An alternate version of the detector, which is specialized towards high-speed applications, has also been developed with slight changes in processing steps. The fast detectors with bandwidth beyond 3 Ghz were demonstrated which provide gain values around 20. The measured risetime was less than 200 ps. Femtosecond pulsed illumination measurements exhibited ultra-low jitter around 15 ps. Transient delay experiments revealed that the measured jitter is due to the transit time in the large absorption region. Hence the amplification process has insignificant time-uncertainty in addition to low amplitude-variance (noise), which is consistent with statistically stable nature of amplification.