Silicon Avalanche Photodiode Research Articles

Negative Wigner function at telecommunication wavelength from homodyne detection

Quantum states of light having a Wigner function with negative values represent a key resource in quantum communication and quantum information processing. Here, we present the generation of such a state at the telecommunication wavelength of 1550nm. The state is generated by means of photon subtraction from a weakly squeezed vacuum state and is heralded by the `click' of a single photon counter. Balanced homodyne detection is applied to reconstruct the Wigner function, also yielding the state's photon number distribution. The heralding photons are frequency up-converted to 532nm to allow for the use of a room-temperature (silicon) avalanche photo diode. The Wigner function reads W(0,0)=-0.063 +/- 0.004 at the origin of phase space, which certifies negativity with more than 15 standard deviations.

Fast x-ray detector system with simultaneous measurement of timing and energy for a single photon

We developed a fast X-ray detector system for nuclear resonant scattering (NRS) experiments. Our system employs silicon avalanche photo-diode (Si-APD) as a fast X-ray sensor. The system is able to acquire both timing and energy of a single X-ray photon simultaneously in a high rate condition, 106 counts per second for one Si-APD. The performance of the system was investigated in SPring-8, a synchrotron radiation facility in Japan. Good time resolution of 120 ps (FWHM) was achieved with a slight tail distribution in the time spectrum by a level of 10-9 at 1 ns apart from the peak. Using this system, we successfully observed the NRS from the 26.27-keV level of mercury-201, which has a half-life of 630(50) ps. We also demonstrated the reduction of background events caused by radioactive decays in a radioactive sample by discriminating photon energy.

Mid-infrared coincidence measurements on twin photons at room temperature

Quantum measurements using single-photon detectors are opening interesting new perspectives in diverse fields such as remote sensing, quantum cryptography and quantum computing. A particularly demanding class of applications relies on the simultaneous detection of correlated single photons. In the visible and near infrared wavelength ranges suitable single-photon detectors do exist. However, low detector quantum efficiency or excessive noise has hampered their mid-infrared (MIR) counterpart. Fast and highly efficient single-photon detectors are thus highly sought after for MIR applications. Here we pave the way to quantum measurements in the MIR by the demonstration of a room temperature coincidence measurement with non-degenerate twin photons at about 3.1 μm. The experiment is based on the spectral translation of MIR radiation into the visible region, by means of efficient up-converter modules. The up-converted pairs are then detected with low-noise silicon avalanche photodiodes without the need for cryogenic cooling.

Brillouin optical time domain reflectometry for fast detection of dynamic strain incorporating double-edge technique

For the first time, to the best of our knowledge, a direct detection Brillouin optical time-domain reflectometry (BOTDR) is demonstrated for fast distributed dynamic strain sensing incorporating double-edge technique, time-division multiplexing technique and upconversion technique. In order to guarantee the robust stability of the system, the double-edge technique is implemented by using a convert single-channel FPI and a fiber-coupled upconversion single-photon detector, incorporating a time-division multiplexing method. The upconversion single-photon detector is adopted to upconvert the backscattering photons from 1548.1nm to 863nm, which is subsequently detected by a Silicon avalanche photodiode (Si-APD). In the experiment, dynamic strain disturbance up to 1.9mε over 1.5km of a polarization maintaining fiber is detected at a sampling rate of 30Hz. An accuracy of ±30με and spatial resolution of 0.6m are realized.

Wavelength dependence of silicon avalanche photodiode fabricated by CMOS process

Avalanche photodiodes fabricated by CMOS process (CMOS-APDs) have features of high avalanche gain below 10V, wide bandwidth over 5GHz, and easy integration with electronic circuits. In CMOS-APDs, guard ring structure is introduced for high-speed operation by canceling photo-generated carriers in the substrate at the sacrifice of the responsivity. We describe here wavelength dependence of the responsivity and the bandwidth of the CMOS-APDs with shorted and opened guard ring structure.

Integration of a 6LilnSe2 thermal neutron detector into a CubeSat instrument

We present a preliminary design for a novel neutron detection system that is compact, lightweight, and low power consuming, utilizing the CubeSat platform making it suitable for space-based applications. This is made possible using the scintillating crystal lithium indium diselenide ($^6$LiInSe$_2$), the first crystal to include $^6$Li in the crystalline structure, and a silicon avalanche photodiode (Si-APD). The schematics of this instrument are presented as well as the response of the instrument to initial testing under alpha radiation. A principal aim of this work is to demonstrate the feasibility of such a neutron detection system within a CubeSat platform. The entire end-to-end system presented here is 10 cm x 10 cm x 15 cm, weighs 670 grams and requires 5 Volts direct current at 3 Watts.

A multi-MHz single-shot data acquisition scheme with high dynamic range: pump-probe X-ray experiments at synchrotrons.

The technical implementation of a multi-MHz data acquisition scheme for laser-X-ray pump-probe experiments with pulse limited temporal resolution (100 ps) is presented. Such techniques are very attractive to benefit from the high-repetition rates of X-ray pulses delivered from advanced synchrotron radiation sources. Exploiting a synchronized 3.9 MHz laser excitation source, experiments in 60-bunch mode (7.8 MHz) at beamline P01 of the PETRA III storage ring are performed. Hereby molecular systems in liquid solutions are excited by the pulsed laser source and the total X-ray fluorescence yield (TFY) from the sample is recorded using silicon avalanche photodiode detectors (APDs). The subsequent digitizer card samples the APD signal traces in 0.5 ns steps with 12-bit resolution. These traces are then processed to deliver an integrated value for each recorded single X-ray pulse intensity and sorted into bins according to whether the laser excited the sample or not. For each subgroup the recorded single-shot values are averaged over ∼107 pulses to deliver a mean TFY value with its standard error for each data point, e.g. at a given X-ray probe energy. The sensitivity reaches down to the shot-noise limit, and signal-to-noise ratios approaching 1000 are achievable in only a few seconds collection time per data point. The dynamic range covers 100 photons pulse-1 and is only technically limited by the utilized APD.

Fast- and low-noise optical receiver for near-infrared light detection and ranging

A fast- and low-noise optical receiver using a silicon avalanche photodiode coupled to a very high-frequency preamplifier circuit is developed, characterized, and tested. The gain, bandwidth, and noise of the preamplifier are optimized to the avalanche photodiode performance to achieve detection and amplification without distortion of the fast and weak optical signal. A low noise level at the preamplifier circuit input of only 1.6 nV/Hz1/2 and a very good linearity from 1 kHz to 280 MHz are achieved. In addition, a good detection performance of the optical receiver is attained: A low-noise equivalent power of only 1.2 pW/Hz1/2 and a minimum signal-to-noise ratio requirement of only 3 are reached. Furthermore, the maximum detection range of the light detection and ranging remote sensing system, using the developed optical receiver, is estimated.

Temporal dependence of transient dark counts in an avalanche photodiode: A solution for power-law behavior of afterpulsing

This paper offers a theoretical explanation of the temperature and temporal dependencies of transient dark count rates (DCRs) measured for a linear-mode silicon avalanche photodiode (APD) and the dependencies of afterpulsing that were measured in Geiger-mode Si and InGaAs/InP APDs. The temporal dependencies exhibit power-law behavior, at least to some extent. For the transient DCR, the value of the DCR for a given time period increases with decreases in temperature, while the power-law behavior remains unchanged. The transient DCR is attributed to electron emissions from traps in the multiplication layer of the APD with a high electric field, and its temporal dependence is explained by a continuous change in the electron emission rate as a function of the electric field strength. The electron emission rate is calculated using a quantum model for phonon-assisted tunnel emission. We applied the theory to the temporal dependence of afterpulsing that was measured for Si and InGaAs/InP APDs. The power-law temporal dependence is attributed to the power-law function of the electron emission rate from the traps as a function of their position across the p–n junction of the APD. Deviations from the power-law temporal dependence can be derived from the upper and lower limits of the electric field strength.

Germanium-tin multiple quantum well on silicon avalanche photodiode for photodetection at two micron wavelength

We report the demonstration of a germanium-tin multiple quantum well (Ge0.9Sn0.1 MQW)-on-Si avalanche photodiode (APD) for light detection near the 2 μm wavelength range. The measured spectral response covers wavelengths from 1510 to 2003 nm. An optical responsivity of 0.33 A W−1 is achieved at 2003 nm due to the internal avalanche gain. In addition, a thermal coefficient of breakdown voltage is extracted to be 0.053% K−1 based on the temperature-dependent dark current measurement. As compared to the traditional 2 μm wavelength APDs, the Si-based APD is promising for its small excess noise factor, less stringent demand on temperature stability, and its compatibility with silicon technology.

Next‐generation solid‐state detectors for charged particle spectroscopy

AbstractThe performance of silicon avalanche photodiodes (APDs) and single crystal chemical vapor deposit diamond detectors (DDs) is reviewed in comparison with conventional silicon‐based solid‐state detectors (SSDs) from the perspective of space plasma applications. Although the low‐energy threshold and the energy resolution are equivalent to SSDs, DDs offer a high radiation tolerance and very low leakage currents due to a wider band gap than silicon. In addition, DDs can operate at higher temperatures, are insensitive to light (>226 nm), and are capable of timing analysis due to the higher intrinsic carrier mobility. APDs also offer several advantageous features. Specifically, APDs have a lower energy threshold (<0.9 keV) and a higher energy resolution (<0.7 keV full width at half maximum at room temperature), along with a linear response due to a strong electric field causing signal amplifications within the detector. Therefore, APDs can be used to detect lower energy particles, covering a larger portion of the energy spectrum than conventional SSDs. Further, the strong internal electric field gives them a subnanosecond response time by the charge mobility saturation, allowing them to make precise timing measurements of ions. These novel detector techniques can be potentially applied to improve the measurements of suprathermal particles, whose energies lie between typical ranges of conventional sensors for low‐energy plasmas and energetic particles. Although the origin and evolution of the suprathermal particles are the key to understanding the acceleration and heating processes in space plasma, they are not well understood due to the technical difficulties of making the measurement.

Enhancing detection sensitivity of SST-1 Thomson scattering experiment

Thomson Scattering System (TSS) is the main diagnostic to extract electron temperature and density of steady state superconducting (SST-1) tokamak plasma. Silicon avalanche photo diode is used with low noise and fast signal conditioning electronics (SCE) to detect incoming Thomson scattered laser photons. A stringent requirement for the measurement is to detect high speed and low level light signal (detection of 100 numbers of Thomson scattered photons for 50ns pulse width at input of active area of detector) in the presence of wide band electro-magnetic interference (EMI) noise. The electronics and instruments for different sub-systems kept in laboratory contribute to the radiated and conductive noise in a complex manner to the experiment, which can degrade the resultant signal to noise ratio (SNR <1). In general a repeated trial method with flexible grounding scheme are used to improve system signal to noise ratio, which is time consuming and less efficient. In the present work a simple, robust, cost-effective instrumentation system is used for the measurement and monitoring with improved ground scheme and shielding method to minimize noise, isolating the internal sub-system generated noise and external interference which leads to an improved SNR.

Interplanetary space weather effects on Lunar Reconnaissance Orbiter avalanche photodiode performance

Space weather is a major concern for radiation-sensitive space systems, particularly for interplanetary missions, which operate outside of the protection of Earth's magnetic field. We examine and quantify the effects of space weather on silicon avalanche photodiodes (SiAPDs), which are used for interplanetary laser altimeters and communications systems and can be sensitive to even low levels of radiation (less than 50 cGy). While ground-based radiation testing has been performed on avalanche photodiode (APDs) for space missions, in-space measurements of SiAPD response to interplanetary space weather have not been previously reported. We compare noise data from the Lunar Reconnaissance Orbiter (LRO) Lunar Orbiter Laser Altimeter (LOLA) SiAPDs with radiation measurements from the onboard Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument. We did not find any evidence to support radiation as the cause of changes in detector threshold voltage during radiation storms, both for transient detector noise and long-term average detector noise, suggesting that the approximately 1.3 cm thick shielding (a combination of titanium and beryllium) of the LOLA detectors is sufficient for SiAPDs on interplanetary missions with radiation environments similar to what the LRO experienced (559 cGy of radiation over 4 years).

Characterizing Silicon Avalanche Photodiode Fabricated by Standard 0.18µm CMOS Process for High-Speed Operation

Characterizing Silicon Avalanche Photodiode Fabricated by Standard 0.18µm CMOS Process for High-Speed Operation

Enhanced solar-blind ultraviolet single-photon detection with a Geiger-mode silicon avalanche photodiode

Solar-blind ultraviolet detection is of great importance in astronomy and industrial and military applications. Here, we report enhanced solar-blind ultraviolet single-photon detection by a normal silicon avalanche photodiode (Si APD) single-photon detector with a specially designed photon-collecting device. By re-focusing the reflected photon from the Si chip surface on the detection area by the aluminum-coated hemisphere, the detection efficiency of the Si APD at 280 nm can be improved to 4.62%. This system has the potential for high-efficiency photon detection in the solar-blind ultraviolet regime with low noise.

Fast scintillation timing detector using proportional-mode avalanche photodiode for nuclear resonant scattering experiments in high-energy synchrotron X-ray region

To obtain both a high count rate of >107s−1 and a detection efficiency sufficient for high-energy X-rays of >30keV, we propose a scintillation timing detector using a proportional-mode silicon avalanche photodiode (Si-APD) for synchrotron radiation nuclear resonant scattering. We here present results obtained with a prototype detector using a lead-loaded plastic scintillator (EJ-256) mounted on a proportional-mode Si-APD (active area size: 3mm in diameter). The detector was operated at ‒35°C for a better signal-to-noise ratio. Using synchrotron X-rays of 67.41keV, which is the same energy as the first excited level of 61Ni, we successfully measured pulse-height and time spectra of the scintillation light. A good time resolution of 0.50±0.06ns (full width at half-maximum) was obtained for 67.41keV X-rays with a scintillator 3mm in diameter and 2mm thick.

Efficient and robust quantum random number generation by photon number detection

We present an efficient and robust quantum random number generator based upon high-rate room temperature photon number detection. We employ an electric field-modulated silicon avalanche photodiode, a type of device particularly suited to high-rate photon number detection with excellent photon number resolution to detect, without an applied dead-time, up to 4 photons from the optical pulses emitted by a laser. By both measuring and modeling the response of the detector to the incident photons, we are able to determine the illumination conditions that achieve an optimal bit rate that we show is robust against variation in the photon flux. We extract random bits from the detected photon numbers with an efficiency of 99% corresponding to 1.97 bits per detected photon number yielding a bit rate of 143 Mbit/s, and verify that the extracted bits pass stringent statistical tests for randomness. Our scheme is highly scalable and has the potential of multi-Gbit/s bit rates.

Precision distance measurement using a two-photon absorption process in a silicon avalanche photodiode with saw-tooth phase modulation.

We present a novel configuration of a precision laser distance measurement based on the two-photon absorption (TPA) photocurrent from a silicon avalanche photodiode (Si-APD). The proposed system uses saw-tooth phase modulation, known as serrodyne modulation, in order to shift the frequency of the reference light from that of the probe light. It suppresses the coherent interference noise between the probe and the reference. The serrodyne modulation also enables lock-in detection of the TPA photocurrent. Furthermore, it contributes to the reduction of the system components. The precision measurement is experimentally demonstrated by measuring a fiber length difference of 2.6 m with a standard deviation of 27 μm under constant temperature. The high-precision displacement measurement is also demonstrated by measuring the temperature-induced change in the optical path length difference of a fiber interferometer.

Radiation-resistant photon-counting detector package providing sub-ps stability for laser time transfer in space

We are reporting on a design, construction and performance of photon-counting detector packages based on silicon avalanche photodiodes. These photon-counting devices have been optimized for extremely high stability of their detection delay. The detectors have been designed for future applications in fundamental metrology and optical time transfer in space. The detectors have been qualified for operation in space missions. The exceptional radiation tolerance of the detection chip itself and of all critical components of a detector package has been verified in a series of experiments.

A Low-Power Photon-Counter Front-End Dedicated to NIRS Brain Imaging

This paper introduces a new miniaturized on-chip photodetector front-end targeted for portable near infrared spectroscopy as a noninvasive tool for real-time brain imaging. It includes silicon avalanche photodiodes (SiAPDs) with dual detection modes using a transimpedance amplifier (TIA) with on-chip gain/bias control, and a controllable mixed (active–passive) quench circuit, with tunable hold-off time, and a novel gated quench-reset technique. This integrated photoreceiver front-end has been fabricated using submicrometer standard CMOS technologies with a minimum fill-factor of 95%. Fabricated SiAPDs exhibit avalanche gains of 35 and 22 at 10 and 18 V bias voltages with red-shifted peak photon-detection efficiency and dark count-rates of 114 and 4 kHz (at 1 V excess bias voltage). The TIA consumes 1-mW power, and offers a transimpedance gain of 250 MV/A, a tunable bandwidth (1 kHz–1 GHz), and an input current referred noise $\surd $ Hz at 1 kHz. The photon-counter exhibits a quench-time of 10 ns with a 0.4-mW power-consumption with an adaptive hold-off time control. The on-chip integration of SiAPDs and front-end circuit, reduced the power-consumption and after-pulsing, and increased the sensitivity.