Photon Detection Research Articles

Proton Predominance At UHE Cosmic Rays Through Analysis Of Different Mass Composition Models

Recently, detection of giant (1017 to 1020eV ) and super giant ( Ep >1020 eV ) air showers is gaining importance as the investigation of EAS in these energy ranges is expected to give necessary information on characteristics of high energy nuclear interactions in one hand and for solving the astrophysical problem of Cosmic Ray origin , beyond the Greisen-Zatsepin-Kuzmin cut-off energy near 1020 eV. Due to the very low Cosmic Ray flux in the UHE range ( > 1017 eV ) direct measurement by balloons or satellites are not possible. The experimental approach realized conventionally uses extended ground-based installations catching data of the induced air showers . An alternative approach is to use a low cost particle detector array called mini-array for detecting UHE cosmic rays by Linsley’s method of arrival time measurement. The miniarray consist of eight plastic scintillation counters covering an area of 2m2 operating for detecting EAS particles of primary energy 1017 -1018 eV based on Linsley’s method of arrival time measurement. An optical detector (5 inch diameter PMT) has been installed at the centre of the miniarray to record the associated optical Cerenkov pulse produced by the ultra-relativistic shower particles in the atmosphere with an aim to derive primary mass composition above 1017 eV. Optical pulses are recorded in one channel of the DSO and the stored data in the wave form memory are transferred to the computer via GPIB interface. The particle detector pulses are triggered with the help of trigger circuit and recorded through other channel of the DSO and transferred to the same DSO. However, the data are subjected to large fluctuation both in particle detection and optical photon detection. Primary energy is estimated through the parameter shower size which is also indirectly measured from a small sample of shower front using miniarray data. Mass composition estimated indirectly relies on simulation model. On the basis of pulse height distribution measurement, the inferred mass composition is predominantly protons, with a tendency of mass composition becoming lighter at the highest energies.

Narrowband Solar-Blind Photodetection of the Plasmonic (In0.3Ga0.7)2O3 Detector via the Synergetic Enhancement of Small-Sized Ag-Nanoparticle Photoabsorbance and Surface Modification.

Currently, research on Ag nanoparticles (AgNPs) predominantly focuses on UV/visible photodetection and UV emission, seemingly overlooking the significance of Ag in enhancing deep ultraviolet photon detection. In this work, (In0.3Ga0.7)2O3 thin films were fabricated by plasma-enhanced chemical vapor deposition. Due to the unique photoabsorbance characteristic and better interaction with photons of small-sized AgNPs, they effectively suppress the UVB absorbance caused by energy band engineering in the (In0.3Ga0.7)2O3 thin film while enhancing photoabsorbance in UVC due to the surface plasmon effect. Therefore, under the synergistic effect of enhanced photon absorbance and hot electron transfer, the performance of the detector is significantly improved, and its responsivity (R), external quantum efficiency, and detectivity (D*) are 193 mA/W, approximately 100%, and 1014 Jones, respectively, at a bias of -6 V. The fast response time and decay time are 634.6 and 194.1 ms, respectively; the rapid decay facilitated by AgNPs is attributed to the increased indirect recombination rate. AgNPs exhibit excellent narrowband response characteristics and absorbance properties in specific wavelength bands for the InGaO photodetector. This research lays the foundation for the practical application of localized surface plasmon resonance-enhanced photon-sensing capabilities.

Correlation avoidance in single-photon detecting quantum random number generators by dead time overestimation

In the case of quantum random number generators based on single-photon arrivals, the physical properties of single-photon detectors, such as time-tagger clocks and dead time, influence the stochastic properties of the generated random numbers. This can lead to unwanted correlations among consecutive samples.We present a method based on extending the insensitive periods after photon detections. This method eliminates the unwanted stochastic effects at the cost of reduced generation speed. We calculate performance measures for our presented method and verify its correctness with computer simulations and measurements conducted on an experimental setup. Our algorithm has low complexity, making it convenient to implement in QRNG schemes, where the benefits of having uncorrelated output intervals exceed the disadvantages of the decreased rate.

Power over fiber development for HEP detectors

Power-over-Fiber (PoF) technology has been used extensively in settings where high voltages require isolation from ground and electromagnetic isolation is critical. In cryogenic environments, PoF offers a reliable power transmission technology, leveraging optical fibers to transfer power with minimal system degradation. PoF technology excels in maintaining low noise levels and isolation when delivering power to sensitive electronic systems operating in extreme temperature ranges and high voltage environments. In a novel application of PoF for a HEP detector, power is provided to photon detector modules located on a surface at ∼300 kV with respect to ground in the planned DUNE experiment. This summary paper of the PoF talk at the 16th PISA Meeting on Advanced Detectors highlights the R&D effort of PoF in extreme conditions and underscores its capacity to revolutionize power delivery and management in critical applications offering a dependable solution with low noise, optimal efficiency, and superior isolation. The DUNE (Abi et al., 2020) experiment will soon deploy large liquid argon (LAr) time projection chambers (TPC) to detect neutrino interactions and other particle physics phenomena. In addition to the particle tracking provided by the TPC, photon detectors, powered by a first ever PoF system, in the cryostat will leverage the high scintillation light yield of LAr to provide crucial timing and additional calorimetric information.

Positronium image of the human brain in vivo.

Positronium is abundantly produced within the molecular voids of a patient's body during positron emission tomography (PET). Its properties dynamically respond to the submolecular architecture of the tissue and the partial pressure of oxygen. Current PET systems record only two annihilation photons and cannot provide information about the positronium lifetime. This study presents the in vivo images of positronium lifetime in a human, for a patient with a glioblastoma brain tumor, by using the dedicated Jagiellonian PET system enabling simultaneous detection of annihilation photons and prompt gamma emitted by a radionuclide. The prompt gamma provides information on the time of positronium formation. The photons from positronium annihilation are used to reconstruct the place and time of its decay. In the presented case study, the determined positron and positronium lifetimes in glioblastoma cells are shorter than those in salivary glands and those in healthy brain tissues, indicating that positronium imaging could be used to diagnose disease in vivo.

Can machine learning reduce the number of anode readouts for reconstruction of coincident single photons in CDIR resistive sea photon detectors?

This study focuses on exploring the potential of Charge Division Imaging Readout (CDIR) for micro-Channel plate (MCP) based resistive sea photon detectors. The CDIR technique spreads the MCP charge footprint capacitively between readout nodes forming anode segments. Charge measurements at each node are then used to reconstruct incident photon’s position and time. A primary objective is to investigate the minimum number of anode segmentation’s necessary, to allow successful reconstruction of multiple photons within a given time interval where pile up would be an issue for traditional approaches. Allowing for optimisation of the anode structure, investigating for a readout schematic to improve timing, rate capability, and reduce distortion effects.Algorithmic and machine learning (ML) techniques will be compared and utilised to reconstruct spatial positions of multiple photons. The comparison will aim to determine if machine learning techniques can be utilised to correct for algorithmic systematic errors to provide a more robust system, whilst removing the need for complex calibrations and allowing for efficient implementation on FPGA in future work.

Gain stability of Hamamatsu R5912-MOD photomultipliers at low temperature

The Photon Detection System (PDS) is a crucial component of the ICARUS detector in the Short Baseline Neutrino (SBN) Program at Fermi National Accelerator Laboratory (FNAL). It consists of 360 PhotoMultiplier Tubes (PMTs) 8” Hamamatsu R5912-MOD and, since June 2020, it has been operating at the liquid Argon cryogenic temperature. During these years, the PMTs have shown gain losses as an aging effect. Using a climatic chamber at the INFN Sezione di Catania, we confirmed a stable gain for a single PMT 8” Hamamatsu R5912-MOD when operated at room temperature, and a persistent gain loss at temperatures around -70 °C, although this temperature is rather higher than that of the liquid Argon.

Traceable characterisation of fibre-coupled single-photon detectors

Abstract The detection of single photons plays an essential role in advancing single-photon science and technologies. Yet, within the visible/near-infrared spectral region, accurate fibre-based optical power measurements at the few-photon level are not yet well-established. In this study, we report on a fibre-based setup, enabling traceable optical power measurements at the few-photon level in this spectral region. The setup was used to calibrate the detection efficiency (DE) of four single-photon avalanche diode (SPAD) detectors. The relative standard uncertainties on the mean DE values obtained from repeat fibre-to-detector couplings ranged from 0.67% to 0.81% (k = 2). However, the relative standard deviation of DE values, which ranged from 1.38% to 3.20% (k = 2), poses a challenge for the metrology of these devices and applications that require high accuracy and repeatability. We investigated the source of these variations by spatially mapping the response of a detector’s fibre connector port, using a focused free-space beam, allowing us to estimate the detector’s spatial non-uniformity. In addition, we realise a novel calibration approach for fibre-coupled SPADs in a free-space configuration, enabling a direct comparison between the fibre-based setup and the National Physical Laboratory’s established free-space facility using a single SPAD. Finally, we investigated alternative coupling methods, testing the repeatability of different fibre-to-fibre connectors in addition to direct fibre-to-detector couplings: SPADs from three manufacturers were tested, with both single-mode and multi-mode fibre.

Quantum double slit experiment with reversible detection of photons

Principle of quantum superposition permits a photon to interfere with itself. As per the principle of causality, a photon must pass through the double-slit prior to its detection on the screen to exhibit interference. In this paper, a double-slit quantum interference experiment with reversible detection of Einstein–Podolsky–Rosen quantum entangled photons is presented. Where a photon is first detected on a screen without passing through a double-slit, while the second photon is propagating towards the double-slit. A detection event on the screen cannot affect the second photon with any signal propagating at the speed of light, even after its passage through the double-slit. After the detection of the first photon on the screen, the second photon is either passed through the double-slit or diverted towards a stationary photon detector. Therefore, the question of whether the first photon carries the which-path information of the second photon in the double-slit is eliminated. No single photon interference is exhibited by the second photon, even if another screen is placed after the double-slit.

Monte Carlo calculations of cryogenic photodetector readout of scintillating GaAs for dark matter detection

The recent discovery that GaAs(Si,B) is a bright cryogenic scintillator with no apparent afterglow offers new opportunities for detecting rare, low-energy, electronic excitations from interacting dark matter. This paper presents Monte Carlo calculations of the scintillation photon detection efficiencies of optical cavities using three current cryogenic photodetector technologies. In order of photon detection efficiency these are: (1) Ge/TES: germanium absorbers that convert interacting photons to athermal phonons that are readout by transition edge sensors, (2) KID: kinetic induction detectors that respond to the breaking of cooper pairs by a change in resonance frequency, and (3) SNSPD: superconducting nanowire single photon detectors, where a photon briefly transitions a thin wire from superconducting to normal. The detection efficiencies depend strongly on the n-type GaAs absolute absorption coefficient KA, which is a part of the narrow beam absorption that has never been directly measured. However, the high cryogenic scintillation luminosity of GaAs(Si,B) sets an upper limit on KA of 0.03/cm. Using that value and properties published for Ge/TES, KID, and SNSPD photodetectors, this work calculates that those photodetectors attached to opposing faces of a 1 cm3 cubic GaAs(Si,B) crystal in an optical cavity with gold mirrors would have scintillation photon detection efficiencies of 35%, 25%, and 8%, respectively. Larger values would be expected for lower values of KA.

Single photon detection up to 2 µm in pair of parallel microstrips based on NbRe ultrathin films

Superconducting microstrip single photon detectors (SMSPDs) are increasingly attracting the interest of the scientific community as a new platform for large area detectors with unprecedented advantaged in terms of fabrication. However, while their operativity at the telecommunication wavelength was achieved, working beyond 1.55 µm is challenging. Here, we experimentally demonstrate single-photon operation of NbRe microstrips at wavelengths of 1.55 and 2 µm. The devices are structured as pairs of parallel microstrips with widths ranging from 1.4 to 2.2 μm and lengths from 5 to 10 μm. This innovative design may assure large sensitive areas, without affecting the kinetic inductance, namely the time performance of the detectors. The results are discussed in the framework of the hot-spot two-temperature model.

Photon Detectors and Emitters for Quantum Communication Systems and Quantum Frequency Standards

Photon Detectors and Emitters for Quantum Communication Systems and Quantum Frequency Standards

Optimized higher-order photon state classification by machine learning

The classification of higher-order photon emission becomes important with more methods being developed for deterministic multiphoton generation. The widely used second-order correlation g(2) is not sufficient to determine the quantum purity of higher photon Fock states. Traditional characterization methods require a large amount of photon detection events, which leads to increased measurement and computation time. Here, we demonstrate a machine learning model based on a 2D Convolutional Neural Network (CNN) for rapid classification of multiphoton Fock states up to |3⟩ with an overall accuracy of 94%. By fitting the g(3) correlation with simulated photon detection events, the model exhibits an efficient performance particularly with sparse correlation data, with 800 co-detection events to achieve an accuracy of 90%. Using the proposed experimental setup, this CNN classifier opens up the possibility for quasi-real-time classification of higher photon states, which holds broad applications in quantum technologies.

Design of an Electronic Interface for Single-Photon Avalanche Diodes.

Single-photon avalanche diodes (SPADs) belong to a family of avalanche photodiodes (APDs) with single-photon detection capability that operate above the breakdown voltage (i.e., Geiger mode). Design and technology constraints, such as dark current, photon detection probability, and power dissipation, impose inherent device limitations on avalanche photodiodes. Moreover, after the detection of a photon, SPADs require dead time for avalanche quenching and recharge before they can detect another photon. The reduction in dead time results in higher efficiency for photon detection in high-frequency applications. In this work, an electronic interface, based on the pole-zero compensation technique for reducing dead time, was investigated. A nanosecond pulse generator was designed and fabricated to generate pulses of comparable voltage to an avalanche transistor. The quenching time constant (τq) is not affected by the compensation capacitance variation, while an increase of about 30% in the τq is related to the properties of the specific op-amp used in the design. Conversely, the recovery time was observed to be strongly influenced by the compensation capacitance. Reductions in the recovery time, from 927.3 ns down to 57.6 ns and 9.8 ns, were observed when varying the compensation capacitance in the range of 5-0.1 pF. The experimental results from an SPAD combined with an electronic interface based on an avalanche transistor are in strong accordance, providing similar output pulses to those of an illuminated SPAD.

Silicon photomultipliers for future HEP experiments

For the particle identification systems of the future high-energy physics detectors, single-photon sensors with sub-mm granularity, high sensitivity, and mitigation strategy for operation in the neutron-irradiated areas are needed. Silicon photomultipliers are considered a baseline technology because of their high photon detection efficiency, good timing resolution, and low operating voltage compared to those of vacuum-based photo sensors. After neutron irradiation, the dark counts increase dramatically and distort the signal baseline, making the single photons indistinguishable. Although the DCR of different unirradiated SiPMs varies, the devices show very similar rates when irradiated to high doses. In this work, we investigated the performance parameters of FBK NUV-HD-RH UHD-DE 1 mm2 devices and determined the working temperature. We show that the maximum operation temperature for samples irradiated with a fluence of 1012 neq/cm2 is around -100°C.

Upgrade of the LHCb RICH detectors and characterization of the new opto-electronics chain

The LHCb detector has been upgraded to manage a five-fold increase in the instantaneous luminosity delivered to the experiment during LHC Run 3 and to readout data at the full bunch crossing rate of 40 MHz. The enhanced LHCb RICH detectors now feature Multianode Photomultiplier Tubes (MaPMTs), covering a total area of approximately 4 square meters, and brand-new frontend electronics to comply with the trigger-less readout architecture. The opto-electronics chain is capable of detecting single photons at repetition rates of up to 100 MHz/cm2 while maintaining an exceptionally low noise. The RICH upgrade is comprehensively outlined, including details about the characterization and studies on the photon detection system. The stability and uniformity achieved by optimizing the parameters of the opto-electronics chain enable the RICH system to function successfully and to provide excellent charged hadron identification in high occupancy conditions.

Robust Pixel Design Methodologies for a Vertical Avalanche Photodiode (VAPD)-Based CMOS Image Sensor.

We present robust pixel design methodologies for a vertical avalanche photodiode-based CMOS image sensor, taking account of three critical practical factors: (i) "guard-ring-free" pixel isolation layout, (ii) device characteristics "insensitive" to applied voltage and temperature, and (iii) stable operation subject to intense light exposure. The "guard-ring-free" pixel design is established by resolving the tradeoff relationship between electric field concentration and pixel isolation. The effectiveness of the optimization strategy is validated both by simulation and experiment. To realize insensitivity to voltage and temperature variations, a global feedback resistor is shown to effectively suppress variations in device characteristics such as photon detection efficiency and dark count rate. An in-pixel overflow transistor is also introduced to enhance the resistance to strong illumination. The robustness of the fabricated VAPD-CIS is verified by characterization of 122 different chips and through a high-temperature and intense-light-illumination operation test with 5 chips, conducted at 125 °C for 1000 h subject to 940 nm light exposure equivalent to 10 kLux.

Results from Cryo-PoF: Power over fiber for fundamental and applied physics at cryogenic temperature

The Power over Fiber (PoF) technology delivers electrical power by sending laser light through an optical fiber to a photovoltaic power converter, in order to power sensors or electrical devices. This solution offers several advantages: removal of noise induced by power lines, robustness in a hostile environment, spark free operation when electric fields are present and no interference with electromagnetic fields.This technology is at the basis of the Cryo-PoF project: an R&D funded by the Italian Institute for Nuclear Research (INFN) in Milano-Bicocca (Italy). This project is inspired by the needs of the DUNE Vertical Drift detector, where the VUV light of liquid argon must be collected at the cathode, i.e. on a surface whose voltage exceeds 300 kV. We developed a cryogenic system, which is solely based on optoelectronic devices and a single laser input line, to power both the Photon Detection devices and its electronic amplifier. The Milano-Bicocca setup employ a commercial GaAs laser source with 2 W maximum power and a photovoltaic power converter with efficiency of ∼ 30% at liquid nitrogen temperature. The results obtained in Milano Bicocca will be presented with emphasis on performance and potential application in the field of applied physics.

A wide dynamic range front-end electronics for SiPMs using high-speed operational and integration amplifiers

Silicon photomultipliers (SiPM) have gained popularity in particle physics due to their inherent advantages in terms of compactness, low power consumption, and high photon detection efficiency. Moreover, we have to deal with signals ranging from a few photoelectrons (PE), where we need to reconstruct the exact shape, up to thousands of PEs in short time intervals.The design of this amplifier was conceived to handle the SiPMs signal in both cases, combining together a high-speed amplifier for precisely reconstruct the shape of the signals of a few PEs and an integrated one in which the output voltage level is directly proportional to the number of the input PEs.

Heralded and Complete Interconversion Between W State and Knill–Laflamme–Milburn State via State‐Selective Reflection with Robust Fidelity

AbstractThe interconversion of different types of entangled states not only can realize the information transmission but also play a significant role in quantum information technologies, including increasing scalability and computational power, and reducing error rates. Here, two protocols for achieving a complete interconversion between W state and Knill–Laflamme–Milburn state assisted by the quantum dot (QD)‐cavity systems and common quantum control gates are proposed. In particular, the protocols employ a heralded approach strategically designed to predict potential failures and facilitate seamless interaction between the QD‐cavity system and photons with the help of a single photon detectors, enhancing experimental accessibility. Through extensive analyzes and evaluations of two protocols, the proposed two protocols achieve remarkable utilization rates of photons (i.e., unit in principle) and achieve near‐unit fidelities and high efficiencies in principle.