Balanced InGaAs/InP avalanche photodiodes for single photon detection

Abstract

We demonstrate a sinusoidally-gated InGaAs/InP photodiode pair operated at wavelength of 1310 nm with high photon detection efficiency (PDE) and low dark count rate (DCR). The photodiode pair is biased in a balanced scenario so that the common component of the output signal is cancelled. The concept of balanced photodiodes helps improve detection efficiency while canceling the common mode signal, which, in this case, is the capacitive response of the photodiodes. In conventional sinusoidal gating, an extra component, -an RF filter (or several) at the gating frequency, is utilized to filter out the gating signal and leave the avalanche signal for detection. For this configuration, sinusoidally-gated counting systems are restricted to a single frequency. With the balanced single photon diodes (SPAD), sinusoidal gating within a continuous frequency range is feasible. A printed circuit with symmetric layout of two bias tees was fabricated on a duroid board to enable the application of AC and DC signals for the dual SPADs. At a laser repletion rate of 1 MHz and temperature of 240 K the DCR and PDE were 58 kHz and 43%, respectively. Afterpulsing probability was lower compared with a sinusoidually-gated single SPAD. Jitter of 240 ps was achieved with 1 photon per pulse for an excess bias of 1.6%.

Pulsed Gating With Balanced InGaAs/InP Single Photon Avalanche Diodes

“…The afterpulse probability versus hold off time does not fit a power law as reported in [11], [20], [27]. The reason is due to the dark count cancellation effect [26]. When dark counts occur simultaneously in the two SPADs they can cancel one another yielding a reduced dark count rate.…”

“…For InGaAs/InP SPADs this can restrict the laser repetition rate to ∼ 100 kHz [17]- [19]. Recently, improved quenching techniques such as selfdifferencing [6], [7], sinusoidal gating [8]- [10], [20], fast gating [13] with matched delay lines [21] or dummy path [14], [15], and balanced detection [22]- [26], have been developed to increase the clock rate of InGaAs/InP SPADs from kHz to GHz [8]- [10], [12], [13], [27]. However, it should be noted that the data transmission rate (i.e.…”

InGaAs/InP Single Photon Avalanche Diodes

“…For sine wave gating the capacitive response of the sinusoidal bias is a sinusoidal signal at the same frequency; therefore, it can be removed by a narrow?band notch filter at the output without affecting the spectrally broad avalanche signal. Previously it has been shown that this approach can achieve high PDE of 55% with DCR of 15.5 kHz at 240 K (15). However, the conventional sinusoidal gating is restricted by the notch filters to a fixed frequency.…”

“…In a conventional sinusoidal gating set up (10,15,16), one of the key components is the band elimination filters, the so?called notch filters. They are designed to eliminate the sine wave gate with minimal affect on the broad band avalanche pulses.…”

“…The conventional sinusoidal gating system is described in reference (15). Two physical modifications were made for this work.…”