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We study an entangled QKD system using photons at 780nm, 1550nm and 4μm from a SPDC nonlinear crystal, over a 30km maritime channel. An analysis of the channel at each wavelength is performed and the QKD system is simulated for each wavelength.
Long bases RT THz standoff spectrometer is designed. GaSe91S0.09:Al(0.03 at.%) DFG of near IR lasers was seeded by THz emission from electronic system. THz generation efficiency was improved by the factor of ≥10 at principally reduced emission bandwidth, and pulse magnitude variation decreased for at least of 4–5 times.
We used a 4-N, N-dimethylamino-4'-N'-methyl-stilbazolium tosylate (DAST) crystal coupled with a Si prism to detect THz pulsed radiation in heterodyne electro-optic sampling scheme. The detection efficiency is higher than that for a DAST crystal without a prism, as well as for a LiNbO3 crystal with a Si prism.
Two recently developed methods that allow visualizing the interaction of THz radiation with arbitrary structures, namely polaritonics and near-field imaging, are reviewed and compared. THz polaritonics, which relies on complex amplified laser systems, allows single-shot image acquisition in a plane perpendicular to the structures. THz near-field imaging, on the other hand, requires only femtosecond...
The effect of pyroelectric polarization was investigated with respect to electron sources and X-ray applications. Different pyroelectric Lithium Tantalate (LiTaO3) crystals were used. Main focus was the optimization of electron emission efficiency in dependence of geometrical parameters, temperature curves and vacuum pressures. The presented results and experimental experiences provide a basis for...
Upconversion detection is a promising technology for measurement of IR signals in the 1.5 μm–2 μm region used for lidar remote sensing [1-2]. In comparison to conventional InGaAs detector, the upconversion detector can achieve IR detection with better signal-to-noise ratio (SNR), not only due to lower dark noise directly, but also because of its limited field-of-view and acceptance bandwidth that...
The mid-infrared domain (MIR) has recently witnessed a renewed interest for a large range of demanding applications such as spectroscopic detection [1, 2]. However, this region still suffers from a lack of low noise, efficient and fast detectors contrary to the visible or near-infrared regions. This has led to the development of an alternative detection scheme based on sum frequency generation (SFG)...
Heralded single photon sources are the subject of intense research owing to their usefulness in metrology and quantum information. These are often created using a pair of photons produced by spontaneous parametric downconversion (SPDC), from which one photon is used to certify the presence of the other. However, multiple-pair production and detector dark counts limit the quality of such sources. Here,...
This paper presents the design and test results of a low-power 10-bit multichannel analyzer (MCA) chip for radiation detection. A low-power and event driven charge sensitive front-end and analog-to-digital converter (ADC) are implemented together with a microcontroller on a single chip. This level of integration leads to a compact MCA that can process and build pulse height spectra when interfaced...
As one of the critical components of intrusion detection devices, the performance of the pyroelectric infrared sensor directly affects the performance of various types of intrusion detectors. In the process of performance progression, strict selection of suitable pyroelectric infrared sensor is essential to intrusion detection device. The performance of the passive infrared intrusion detectors, active...
This work introduced a novelty MEMS pyroelectric infrared detector based on LiTaO3 (LT) crystal with high absorptivity amorphous carbon film layer. The LT crystal is thined and polished to 100um thickness and double mentaled for electical connection which will be suspened upon rectangle cave of silicon substrate with mental ring. Amorphous carbon(a-C) could be produced by magnetron sputtering on the...
Piezoelectric ringing effect in beta barium borate (BBO) Pockels cell crystals, which reduces the contrast ratio of cell, has been investigated. The experimental model for the measurement of the piezoelectric ringing impact on the Pockels cell contrast ratio was created. The investigations of Pockels cell contrast ratio dependence on applied high-voltage pulse frequency for BBO crystals of three different...
Components of complex dielectric permittivity of semi-insulating Cd1−xZnxTe crystals had been measured in the dark and under photo excitation. Also we studied energy resolution of radiation detectors made from these crystals for 137Cs quants. Present studies have been carried out taking into account using specimens from different regions of crystal ingot. It is ascertained that investigated values...
In PET systems with a geometry different from a closed ring, the Time of Flight (TOF) of the annihilation photons appears to be relevant. Such a system capability helps to compensate the missing angular information that generates artifacts on the reconstructed images. In this work, two ASIC designs are evaluated for their use in PET systems having accurate coincidence resolving times (CRT) while preserving...
The need for simultaneous neutron and gamma detection continues to motivate the development of dual mode radiation detectors. One promising candidate is the elpasolite inorganic scintillator Cs2LiYCl6:Ce (CLYC). Previous studies, with other dual neutron–gamma detectors (EJ-299/EJ-309), have shown that the choice of digital data acquisition (DAQ) system can significantly affect pulse shape discrimination...
A novel single-ended-readout depth-of-interaction (DOI) detector is proposed for application in positron emission tomography (PET). The crystal unit of this detector is formed by a transform of the crystal unit of a dual-ended readout detector, which is constructed from a LYSO scintillator pillar segmented using sub-surface laser engraving (SSLE). Specifically, two scintillator pillars are coupled...
In this paper, we further explore the optical property modulation-based method for ionizing radiation photon detection in PET as a potential new direction to dramatically improve the coincidence time resolution. We compare the performance of three detector crystals for this method including two types of cadmium telluride (CdTe) crystals and one bismuth silicon oxide (BSO) crystal under high bias voltages...
Laser Induced Optical Barriers (LIOB) is a promising technique for fabrication of high resolution and high sensitivity scintillator detectors for Positron Emission Tomography (PET). With LIOB local changes in refractive index may be introduced inside the bulk of a monolithic crystal by using a tightly focused pulsed laser. One major advantage of LIOB compared to standard mechanical pixelation techniques...
We previously built a high-resolution PET scanner (PawPET) using 8 mm thick Lutetium Oxyorthosilicate (LSO) detectors, but it suffers from poor sensitivity. From our prior work we know that unpolished 0.5 mm pitch arrays with Toray reflector are challenging to decode at depths greater than 8 mm. We hypothesize that decoding will improve by polishing the crystal surfaces. We also know that polished...
A series of small size 22Na point sources have been simulated using GATE, following the NEMA protocol, and applied to the geometry of a brain dedicated PET so-called MindView. The simulated scanner geometry is currently composed by one ring of 20 detector blocks with a distance of about 330 mm between opposite detectors. Each detector module includes a monolithic LYSO crystal of 50 × 50 × 20 mm3 and...
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