The comparative characteristics of highly sensitive photodetectors for modern lidar systems, like self-driving vehicles and autonomous systems for collision avoidance, sensors for aircraft and marine vessels, atmospheric lidar sensing systems, topographic mapping tools are considered. Estimates of the basic parameters of photodetectors such as sensitivity threshold, dynamic range, time and amplitude resolution, as well as the effect of background light on sensitivity were made for the new-type experimental detector HD-SiPM (high-density silicon photomultiplier) and compared with the APD module and commercial SiPM devices, optimized for ToF LiDAR application. Comparison results show that the HD-SiPM looks promising for application in various ToF LiDAR systems.

In this paper, we analyze the influence of the crosstalk level and the dynamic range on the basic characteristics of a silicon solid-state photomultiplier and demonstrate their importance for detecting of optical signals with backlight illumination, in particular, for LIDAR application. Experimental results obtained in the study of threshold and fluctuation parameters of detectors with different levels of crosstalk and dynamic range are presented. It is shown that the detector design combining a high dynamic range with a small crosstalk gives a noticeable advantage in such applications.

The new-type silicon photomultiplier with high density of cells (HD-SiPM) was developed by DEPHAN for the task of analog detecting of short light pulses. In this work we have tested and compared with known references its responsivity, amplitude and time resolution by short laser pulses (442 nm) in a wide range of signal intensities. The results demonstrate, that the new detector could be interesting for Hi-Res Medical Imaging and other pulse detecting applications in nuclear science, especially those requiring combination of sensitivity, high speed and dynamic range from a small-area detector or an array element.

One of the most important problems of detecting weak light pulses is the determination of the accurate signal transit time. In this case, photodetectors capable of detecting single photons are characterized by two main parameters: the photon detection efficiency and transit time spread. A unified technique for measuring these parameters is proposed. The technique is based on the probabilistic distribution of transit times, which allows separation of characteristics of single-photon processes as multiphoton light pulses are fed and under conditions of high dark noises, which seems important, in particular, when operating with solid-state photomultipliers.

Solid-state photomultipliers (SSPMs) is a new type of semiconductor avalanche photodetectors operating in the Geigermode with negative feedback and allowing detection of individual photons. In recent years, SSPMs are increasingly widely used in nuclear physics, high-energy physics, medicine, biology, and other fields, replacing vacuum photomultipliers and avalanche photodiodes (APDs). The negative feedback in SSPMs provides a high multiplication factor (105–106) and an ultralow noise factor (1.01–1.05); however, noises of crosstalk and afterpulsing processes come to the fore in this case. In this communication, we present the results of experimental measurements of crosstalk processes in various SSPM samples and analyze the measurement techniques.

Paramagnetic complexes CuL 1 SO 4 ·0.5H 2 O, CuL 2 SO 4 ·2H 2 O and diamagnetic Pd(HL 2 )Cl 3 (L 1 = 2-methyl-1,3,11,11 c -tetraazacyclopenta[ c ]phenanthrene complex (L 2 = 2-phenyl-1,3,11,11 c -tetraazacyclopenta-[ c ]phenanthrene) were synthesized. The most probable structure of the complexes was suggested on the basis of the IR and ESR spectra. Coordination units of paramagnetic complexes contain N atoms of the bidentate cycle-forming ligands, L 1 and L 2 molecules. The square PdCl 3 N unit of the diamagnetic complex includes the N atom of the triazole fragment of the monodentate ligand, (HL 2 ) + cation.

Solid-state photomultipliers (SSPMs) are a new type of photodetectors based on avalanche breakdown of the semiconductor in the Geiger mode, limited by negative feedback. Under such conditions, the avalanche breakdown is characterized by high multiplication factors, 104–106, and low noise, which allows detection of single photons. However, in practice, each primary breakdown in the SSPM can be accompanied by secondary breakdowns due to cross-talk processes which change the probabilistic distribution of the signal and introduce excess noise. In this paper, the effect of cross-talk on signal and noise characteristics of SSPMs is considered based on the generalized Poisson distribution.

We describe a new type of a sensitive semiconductor photodetector that could be used in medical imaging applications. The photodetector, based on the mechanism of discrete amplification, has performance parameters comparable to, and for some applications exceeding, those of the vacuum photomultiplier tubes. High amplification gain achieved at very low levels of excess noise is accompanied by the fast speed and high dynamic range of the photodetector. Comparison of the technology with classic arrays of Geiger-mode APD arrays is also performed.

Recent advances in bio-optical methods for Medical Diagnostics, Optical Biopsy and Non-Invasive Imaging have the potential to prolong and improve the quality of life while significantly reducing medical costs for the diagnosis and tracking of diseases. Advances in the Genomics and pharmaceutical discovery using micro-array technology and High Throughput Screening permit to study thousands of compounds in short periods of time. This paper presents a new Si-based photonic sensors and sensor arrays with internal discrete amplification that offers the necessary qualities thus allowing development of a new generation of high gain, ultra low noise, universal analog and counting photodetectors for bio-optical sensing applications. The new photodetectors can operate in the linear detection mode with a gain-bandwidth product of up to 10(15)/sec and in the photon counting mode with count rates of up to 109 counts/sec. Detectors based on this amplification mechanism could have performance parameters superior to those of conventional avalanche photodiodes and photomultiplier tubes. For tested silicon photodetector prototypes, measured excess noise factor is as low as 1.02 at gains greater than 100,000.

The detection and identification of single molecules represent one of the ultimate goals of analytical chemistry. We have designed, developed and tested a new family of photodetectors with Internal Discrete Amplification (IDA) mechanism. These photodetectors can operate in linear (analog) detection mode with gain-bandwidth product up to 5.10(14) and one- or few-photon sensitivity, as well as in the photon counting mode with count rates up to 10(8) cps. Their key performance characteristics exceed those of photomultiplier tube (PMT) and avalanche photodiode (APD) devices. The measured parameters of the detectors are: gain >10(5), excess noise factor as low as 1.02, maximum count rate >10(8) counts/s, and rise/fall time < 300 ps. The new family of the photo detectors may become an ideal solution for the problems of ultrasensitive and single-molecule detection by fluorescence spectroscopy and other optical methods.

We demonstrate the feasibility of applying the emerging technology of internal discrete amplification to create an efficient, ultra low noise, universal analog and counting photodetector for LIDAR remote sensing. Photodetectors with internal discrete amplification can operate in the linear detection mode with a gain-bandwidth product of up to 1015 and in the photon counting mode with count rates of up to 109 counts/sec. Detectors based on this mechanism could have performance parameters superior to those of conventional avalanche photodiodes and photomultiplier tubes. For silicon photodetector prototypes, measured excess noise factor is as low as 1.02 at gains greater than 100,000. This gives the photodetectors and, consequently, the LIDAR systems new capabilities that could lead to important advances in LIDAR remote sensing.

Novel integrated intelligent videosensor and its possible application using on-FPA real-time parallel processing are discussed. This solid-state single-chip sensor is photoelectric structure with memory (PESM), which consists of semiconductor, insulator and metal layers, wherein optical information are detected, recorded and stored in the form of 2D charge and potential patterns, and then processed due to internal interaction of these patterns in a normal direction to the input plane. Thus, such Z-plane technology allows the PESM to operate as multifunctional device utilizing massively parallel processing with high effective operational speed (up to 1014 operation/bit/s) without additional electronic and computing units. Except reading, writing and storing, PESM performs such parallel image processing as summation, subtraction, contouring, convolution and correlation, which may be effectively applied to numerous tasks of diverse optoelectronic systems. Two image operations--subtraction and correlation, which seems to us of high importance, are demonstrated as an example of the PESM performance. It allows one to solve in a real time the main problems concerned with background subtraction, moving object selection, target tracking and pointing, recognition of extended objects and so on. As we suppose, the possible applications of the PESM as an intellectual `supersensor', which combines a high-quality imager and a high-capacity multifunctional processor, would provide substantially lower prime cost of the designed systems in comparison with the now-existing ones and may be widely extended.

Innovative approach to signal processing of the small targets under complicated conditions including low-contrast and maneuvering targets with backgrounds is presented. Its essence is dealt with the use of intelligent solid-state photosensor, so-called photoelectric structures with memory (PESM). PESM is integrated multilayer heterostructure, which combines the main capabilities of photodetector, imager, memory media and parallel processor. Optical information signal is detected in photosensitive layer, recorded and stored as 2D charge pattern in memory layer, read out from reading layer, and processed due to charge, potential and electric field pattern interactions throughout the PESM layers. PESM performs such parallel image processing as summation, subtraction, contouring, convolution and correlation, which may be effectively applied to numerous tasks of diverse photonic systems. It is essential, that PESM performs such multifunctional operations in a real time without any additional processors and computers.

Novel integral videosensor and its possible application for real-time operation in machine vision, robotics, and visual communication are discussed. This sensor is a solid-state photoelectric structure with memory (PESM), which consists of semiconductor, insulator, and metal layers, wherein visual information is registered, stored, and processed as 2D charge and potential patterns. So, the PESM operates as a multifunctional device utilizing massively parallel processing due to internal interactions between charge and potential patters, induced electric fields, and incident illumination. That is why it may be effectively applied to the real- time visual processing optoelectronic systems. In this report we would like to propose some ideas and methods of the PESM applications in intellectual machine vision system. The basic image operations of the PESM, namely subtraction and correlation, allows one to solve in real time the main problems concerned with the selection of a required object with subsequent tracking, pointing, and guidance. It is essential that in these and similiar PESM applications for the optoelectronic system the usage of additional electronics is minimized, involving its substantially lower prime cost compared with the now existing systems. As we suppose, the possible applications of the PESM as an intellectual 'supervideosensor' that combines a high quality imager and a high-capacity processor, may be widely extended.

Possible use of photoelectric structures with memory (PESM) in airborne reconnaissance is discussed. It is shown that basic PESM properties and operation abilities can be used for solving widespread image processing tasks such as image contouring, correlation, moving object selection, object dynamics determination, and so on. These and other operation modes of the PESM can be realized without any computer processing in real time. Being an integrated highly intelligent low-cost videosensor-and-processor device the PESM is capable of executing many tasks in total and local surveillance missions. PESM application for unmanned and small lifetime target observation is an especially good prospect.

The present paper discusses a fundamental new approach to creation of universal, multi- purpose devices capable of registering, storing, converting, and processing images -- photoelectric structures with memory (PESM). Its essence is the development of integral multilayer solid-state structures, wherein optical information is registered and stored as a 2-D charge and potential pattern in the plane of the layers, and is transferred and converted in a perpendicular direction due to interaction of these patterns. Different layers of the structure are intended for performing different specific functions which makes it possible to design, modify, and optimize the PESM variants with reference to a wide range of specific problems so as to attain the most efficient functioning of the separate layers.

In this paper the basic physical principles of new research methods, namely the study of generation centers and spatial inhomogeneities in MIS structures with the aid of avalanche multiplication, are reported.

A memory effect is observed when a nickel-zinc selenide–germanium structure is irradiated by light of different spectral composition. The effect is based on the recharging of trapping sites in a ZnSe layer both, by electrons and holes. The long-wave boundary, for the first process, is determined by the energy barrier Ni Fermi level-ZnSe conduction band bottom. For the second process it is the barrier Ni Fermi level–ZnSe valence band top. Their values, found by the procedure proposed earlier, are 1.07 and 1.27 eV, respectively. [Russian Text Ignored].

A method is presented for studying the generation phenomena in strong fields (105 to 106 V/cm) under avalanche conditions. This allows one to determine the value of the initiating generation current (IGC) in the avalanche process, and to analyze its behaviour with respect to supplied voltage. Irregularities of the dark generation current arising with the injection of hot carriers into an insulator are shown to be due to the charge exchange between slow surface states and a space charge layer. A model of the generation center and its discharge behaviour is devised. According to this model the generation center depth and the energy position are found. Energy level of the generation center coincides with the peak of fast DOS extracted from quasi-static C-U measurements with an accuracy up to 0.1 eV. [Russian Text Ignored].