Photon Detection Technique Research Articles

System for the fast readout and tests of pixel IC operating in single photon counting mode using PCIe-based FPGA

Hybrid Pixel Detectors (HPDs) have become popular in particle and photon detection techniques in recent years. This type of devices consists of two parts: a pixelated sensor (based on Si, Ge, GaAs, CZT, etc.), and a readout Integrated Circuit (IC), which usually contains thousands of pixels and millions of transistors. ICs suffer from the inaccuracies of manufacturing processes, therefore HPDs have to be thoroughly tested before the sensor bump-bonding process. This paper presents a highly efficient system for the automated testing of pixelated HPDs. The presented solution is based on the Intel Arria 10 GX Field Programmable Gate Array (FPGA) development kit and a Linux-powered Personal Computer (PC), connected via Peripheral Component Interconnect Express (PCIe) 8x Gen. 3 interface. The proposed system has been built of well-thought-out modules connected through the set of precisely defined interconnects. This approach enabled the development of an architecture that may be easily implemented in both PCIe-based systems and System-on-Chip devices, such as Intel Agilex SoC. The presented system has been tested with both a manufactured IC and a model implemented in the FPGA.

Material Imaging Via X-RAY Emitted from laser produced plasma

The present work represented to the new idea techinque of imaging material through X-ray emitted from laser produced plasma, here, the plasma intensity in uv-visible region spectrum was measurment from the interaction of the 1.06μm of nedumium-glass laser pulse duration of energy 4J, with five target laser: Al, Cu, C, Pb and Stainless Steel(St.St). Astudy of the X-ray emission intensity as a function of laser produced plasma density and surrouding pressure has been a complished using a high sensitive photon detection and counting technique assoicated with an X-ray intensifying screen whose function is based on X-ray florescence. the stainless –stell target was found to have the highest plasma emission intensity, and as a result it has higher X-ray emission intensity. the results show that the plasma X-ray emission intensity is increased with decreasing surrouding pressure, while this emission intensity is increased with increasing the laser power density. In order to study the spatial scanning of transmitted plasma X-ray intensity and study the factors affecting the x-ray imaging process, a special designed Cu specimen of varying thickness was used. The spatial scanning of transmitted x-ray emission intensity shows a comparative picture to the Cu specimen from the recorded x-ray intensity, in which it decreases at thicker region acorrding to lamberts absorbtion law.

Deterministic Secure Four-qubit GHZ States Three-step Protocol for Quantum Communication

A deterministic secret quantum communication (DSQC) protocol is proposed with four-qubit GHZ states. It has some outstanding advantages. Firstly, it has a high communication capacity as each four-qubit GHZ state can carry three bits of secret messages. Secondly, as all of the quantum resource is useful, the intrinsic efficiency of the communication approaches the maximum value 100%. Besides, its total efficiency of the present protocol is 60%, more higher than most of the current existing DSQC protocols. The decoy photon detection technique guarantees that Eve’s any eavesdropping behavior can be detected on site, and the three-step transmitting strategy ensures no information will be leaked in the communication process. Moreover, the present protocol is feasible with the present day technique.

A wide dynamic range and high resolution all-fiber-optic turbidity measurement system based on single photon detection technique

A high-resolution fiber-optic detection system has been developed to measure the wide dynamic range of turbidity. To obtain high-resolution measurement results, a high sensitive single photon detection technique (SPDT) has been used in the system. Based on fiber characteristics, a compact probe structure for fiber-optic integrated transceiver (FITP) is designed to transmitting and collection light signal, which has the capability of detecting turbidity in the narrow workspace. By combining the Beer-Lambert (B-L) law transmission law with single photon counting theory, a novel turbidity measurement theoretical model has been proposed, which shows a good exponential relationship over the whole measurement range from 0.01 to 1000 NTU (Nephelometric Turbidity Units). However, when detecting 0.01–0.1 NTU low turbidity, the experimental results turn into an approximate linear relationship, which good agrees with the proposed theoretical model. Last, some issues about the optimization of light intensity and requiring attention on constructing a practical distributed multi-point water turbidity remote monitoring system in the outdoors are also discussed. It was found that the system can achieve a measurement dynamic range as wide as 50 dB with a resolution better than 0.01 NTU in the range of 0.01–1000 NTU, which is suitable for some specific turbidity measurement in remote and narrow workspace.

Photophysical properties of flavonoids extracted from Syngonanthus nitens, the golden grass

Dry stems of Syngonanthus nitens, a plant of the Euriocaulaceae species, present exquisite golden shine, originated from flavonoids residing at S. nitens stem epidermis. We report here on the optical properties of flavonoids extracted, in different solvents, from dry stems of the plant. The extracts were analyzed by UV–Vis absorption and fluorescence emission spectroscopies, and data were obtained in solvents of different polarity and in aqueous media at different pHs. Time-resolved fluorescence experiments, made using single photon detection technique, fluorescence correlation spectroscopy and fluorescence anisotropy measurements were also employed to study flavonoid/solvent and flavonoid/flavonoid interactions. A consistent picture of the S. nitens flavonoid photophysical behavior and their interaction via proton transfer in aqueous suspension is obtained. The results are important to understand the photophysical process involving flavonoids in general.

The design of rapid turbidity measurement system based on single photon detection techniques

Abstract A new rapid turbidity measurement system has been developed to measure the turbidity of drinking water. To determinate the turbidity quantitatively, the total intensity of scattering light has been measured and quantified as number of photons by adopting the single photon detection techniques (SPDT) which has the advantage of high sensitivity. On the basis of SPDT, the measurement system has been built and series of experiments have been carried out. Combining then the 90° Mie scattering theory with the principle of SPDT, a turbidity measurement model has been proposed to explain the experimental results. The experimental results show that a turbidity, which is as low as 0.1 NTU (Nephelometric Turbidity Units), can be measured steadily within 100 ms. It also shows a good linearity and stability over the range of 0.1–400 NTU and the precision can be controlled within 5% full scale. In order to improve its precision and stability, some key parameters, including the sampling time and incident light intensity, have been discussed. It has been proved that, to guarantee an excellent system performance, a good compromise between the measurement speed and the low power consumption should be considered adequately depending on the practical applications.

High-throughput time-correlated single photon counting.

We demonstrate time-correlated single photon counting (TCSPC) in microfluidic droplets under high-throughput conditions. We discuss the fundamental limitations in the photon acquisition rate imposed by the single photon detection technique and show that it does not preclude accurate fluorescence lifetime (FLT) measurements at a droplet throughput exceeding 1 kHz with remarkable sensitivity. This work paves the way for the implementation of innovative biomolecular interaction assays relying on the FLT detection of nanosecond-lived fluorophores for high-throughput biotechnological applications, including high-throughput screening or cell sorting potentially allowed by droplet microfluidics or other fast sample handling facilities.

Photodiode optical to electrical signal delay

We are presenting the experiment and its results showing a temporal relation between optical input and electrical output of a photodiode. The presented results are a byproduct of more complex experiment to identify absolute delay contributors in picosecond time-resolved single photon detection technique. This particular result is not limited to extremely weak optical signals and can be applied in any picosecond time-resolved experiments with sufficient detected information.

Distillation of mixed-state continuous-variable entanglement by photon subtraction

We present a detailed theoretical analysis for the distillation of one copy of a mixed two-mode continuous-variable entangled state using beamsplitters and coherent photon-detection techniques, including conventional on-off detectors and photon number resolving detectors. The initial Gaussian mixed-entangled states are generated by transmitting a two-mode squeezed state through a lossy bosonic channel, corresponding to the primary source of errors in current approaches to optical quantum communication. We provide explicit formulas to calculate the entanglement in terms of logarithmic negativity before and after distillation, including losses in the channel and the photon detection, and show that one-copy distillation is still possible even for losses near the typical fiber channel attenuation length. A lower bound for the transmission coefficient of the photon-subtraction beamsplitter is derived, representing the minimal value that still allows to enhance the entanglement.

Ultra sensitive sensor with enhanced dynamic range for high speed detection of multi-color fluorescence radiation

This paper describes design of the new ultra sensitive sensor system for fluorescence detection applications. System comprises two units: optical spectra separation unit and detection unit. Optical unit of the sensor performs spatial spectra separation of signal from the laser excited fluorescence, and resulting spectra is collected in the detection part of the system. Optical part is built using diffraction grating as spectra separation element. Detection part comprises 32-channel photomultiplier tube working in single photon counting mode with our 32-channel amplifier. Using single photon detection technique and specific signal processing algorithms for collected data, the proposed system allows to achieve unique combination of characteristics—high sensitivity, high detection speed and wide linearity dynamic range comparing to existing commercial instruments. DNA sequencing experiments with new sensor as detection device, and using two types of lasers (Ar-ion and Nd-YAG) were carried out, yielding sequencing traces which have quality factor of 20 for read lengths as long as 650 base pairs.

First photon detection in transillumination imaging: A theoretical evaluation

This thesis is a theoretical evaluation of the (single) first photon detection (FPD) technique as a limiting case of time‐resolved transillumination imaging (TI) for diagnostic purposes. It combines analytic and Monte Carlo (MC) simulation methods to derive the single photon statistics and to solve the radiative transfer equation (RTE) for a given source‐medium‐detector geometry. In order to efficiently simulate very early arriving photons, an Indeterministic Monte Carlo (IMC) technique based on path integrals is devised and validated. The IMC extends controlled MC techniques to accelerate and enhance the probability of detecting shorter trajectories thereby improving the statistics. The IMC technique provides a tool for the construction of a temporal point spread function (TPSF) of the emerging photons for the entire time scale. It is then used to predict the spatial resolution of these systems for shorter (sub‐100 picosecond) time scales. The calculation of the TPSF at short time scales for a pulse made incident onto the medium enables the mathematical derivation of the temporal probability density functions (p.d.f.) for the first arriving photon, This facilitates the investigation of a first photon detection (FPD) system as applied to a diagnostic TI configuration. A FPD system produces a signal representing from which the mean transit time of the first arriving photon, may then be estimated for a sequence of incident pulses at each scan position. By rectilinear scanning across the medium, a two‐dimensional (2‐D) map of can be created and displayed as a gray scale image. The application of FPD to TI is evaluated assuming an ideal detector capable of detecting the first arriving photon with 100% efficiency (infinite extinction coefficient). However, a model for a FPD system corresponding to a nonideal (single first photon) detector is also considered through the evaluation of the p.d.f. for the later (first, second,…) arriving photons. This enables a detection time limit to be specified to eliminate the later arriving photons and thereby overcome distortions in the first photon p.d.f., which may be caused by any inefficiency in the response of the detector. The FPD technique is then applied to obtain for various laser pulse intensities. The FPD system is also examined for the case of spherical inhomogeneities (representing tumors) embedded in the center of an otherwise homogeneous medium. The effect of the variations in the embedded inhomogeneity (size and optical density) and optical properties of the medium are also studied. A heterogeneous medium that resembles tissue more realistically is considered. For a FPD system where the received signal does not change (one photon) per incident pulse, the signal contrast is redefined and is examined as a function of the incident laser power and medium absorption and scattering properties. The signal–noise‐ratio is also evaluated for the FPD system as the error in the estimation of Based on the analysis of the SNR, the number of incident pulses (per scan position), needed to achieve a required SNR, is also derived. It is shown that the p.d.f. of the first arriving photon for a totally absorbing inhomogeneity located at the midplane of a 50 mm thick tissue‐like medium may be distinguished (95% confidence level) from the p.d.f. of a medium without the inhomogeneity. This theoretical study provides an introduction aimed at assisting further experimental research into the limits of transillumination imaging employing a first photon detection (FPD) system.

Photon Production in Au+Au Collisions at $\sqrt{s_{NN}}$ = 130 GeV

We report raw photon, neutral pion and eta measurements at RHIC. Photons in the energy range from 100MeV − 4GeV were detected by reconstructing e + e − pair production, γ+Z→e ++e −+Z, with the STAR Time Projection Chamber (TPC). Along with the photon detection technique we discuss the purity of the photon candidates and measurements of hadronic decays via their electromagnetic decay channels. The π0→γ and η→γγ decay channels are addressed.

Experimental System for Quantum Cryptography Based on Two Nonorthogonal Photon Polarization States

Quantum cryptography allows the establishing of a highly confidential sequence of random bits between two parties who share no secret information in advance. Its security is guaranteed by the basic laws of quantum mechanics rather than mathematical difficulty. An experimental system based on a novel protocol for quantum cryptography using only two nonorthogonal photon polarization states is implemented. The photon sources are two semiconductor laser diodes operated at 680 nm, their light pulses which are heavily attenuated to far below one photon per pulse are employed to encode the key. Gated single photon detection technique is used to minimize the dark count effect of the photon multiplier tube. Key establishing rate of 40 b/s and error rate of 2.1% are obtained. Compared with other systems, our system has the simplest experimental setup.

Quantitative measurement of light emission during the early stages of electrical breakdown in epoxy and unsaturated polyester resins

Quantitative light emission studies of the initiation and early growth stages of electrical treeing in synthetic resins have been undertaken to gain insight into the underlying physical mechanisms responsible for these processes. Mains-synchronous photon detection techniques coupled with an ultra-sensitive photomultiplier and large-area light collection optics were used to measure the low-level light emission from pin-plane CT200 epoxy and polyester specimens subjected to 50 Hz AC step ramp electrical stress. Three types of light emission are observed consistently and correspond to (i) electroluminescence related to charge injection (Fowler-Nordheim or Schottky depending on the local electric field), (ii) microdischarge activity with formation of microchannels and (iii) conventional partial discharge activity during tree growth. No material-dependent threshold voltage/field was found for electroluminescence and hence charge injection in these materials.

High resolution and efficiency annihilation photon detection with a multi-element BGO converter and two dimensional optical readout

An annihilation photon detection technique using an array of small, optically decoupled BGO crystals as converter and a two dimensional optical readout has been investigated. The readout comprised a microchannel plate image intensifier coupled to a Reticon RA-100 photodiode array. Tests on a target of 25 2 mm square, 1 cm long elements, packed in a 5 by 5 array, have shown that scintillation light from 0.66 MeV photons is localized in individual elements. Spatial resolution is thus, on the millimetre scale, limited by element dimensions. Compton scattering in the converter degrades spatial resolution and/or detection efficiency. Simulations show that an efficiency >40% may be expected for unambiguous reconstruction of photon interaction coordinates in an array of 2 mm square, 2 cm long crystals.

Coaxial nanosecond flashlamp

We have developed a coaxial thyratron-gated flashlamp capable of being operated with high stability over a much wider range of conditions than previous flashlamps. Novel methods for continuously monitoring discharge stability are described. We present comprehensive data on the dependence of pulse width and intensity on operating parameters. Using the single photon detection technique an overall instrumental profile of 950 ps FWHM and 630 ps rise time has been obtained using hydrogen as a filler gas. An instrumental width of 1.2 ns FWHM can be routinely obtained in nitrogen even at a repetition rate of 100 kHz. Intensities of ≳109 photons per pulse in nitrogen and ≳108 in hydrogen can be obtained at the minimum pulse duration. The maximum intensity per pulse without added capacitance is ≳1010 photons. This performance is considerably better than that reported for conventional flashlamps.

Position-Sensitive Detection of Extreme Ultraviolet Photons

Recent advances in photon detection techniques for the extreme ultraviolet region have been highlighted by the introduction of multichannel electron multipliers and image-sensing detector arrays. Current and potential applications for such position-sensitive detectors in vacuum-ultraviolet and extreme ultraviolet spectroscopy are discussed in this paper. Examples are presented of multichannel spectra of several highly-ionized atoms obtained using fast-ion spectroscopy.