Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 342
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

Operation of an electrically controlled beam steering device based on Rochon prism made by use of nematic liquid crystal is modelled numerically. Deflection angles and angular distribution of light intensity in the deflected beam are calculated. Dynamics of the device is studied. Advantage of application of dual frequency nematic liquid crystal is demonstrated. Role of flexoelectric properties of the nematic is analyzed.

Go to article

Authors and Affiliations

M. Buczkowska
G. Derfel
Download PDF Download RIS Download Bibtex

Abstract

We report on the first application of the graphics processing units (GPUs) accelerated computing technology to improve performance of numerical methods used for the optical characterization of evaporating microdroplets. Single microdroplets of various liquids with different volatility and molecular weight (glycerine, glycols, water, etc.), as well as mixtures of liquids and diverse suspensions evaporate inside the electrodynamic trap under the chosen temperature and composition of atmosphere. The series of scattering patterns recorded from the evaporating microdroplets are processed by fitting complete Mie theory predictions with gradientless lookup table method. We showed that computations on GPUs can be effectively applied to inverse scattering problems. In particular, our technique accelerated calculations of the Mie scattering theory on a single-core processor in a Matlab environment over 800 times and almost 100 times comparing to the corresponding code in C language. Additionally, we overcame problems of the time-consuming data post-processing when some of the parameters (particularly the refractive index) of an investigated liquid are uncertain. Our program allows us to track the parameters characterizing the evaporating droplet nearly simultaneously with the progress of evaporation.

Go to article

Authors and Affiliations

D. Jakubczyk
S. Migacz
G. Derkachov
M. Woźniak
J. Archer
K. Kolwas
Download PDF Download RIS Download Bibtex

Abstract

The main objective of this work is to characterize the performance of an interferometric fibre sensor which has been designed in order to register rotational phenomena, both in seismological observatories and engineering constructions. It is based on a well-known Sagnac effect which enables to detect one-axis rotational motions in a direct way and without any reference system. The presented optical fibre sensor – FOSREM allows to measure a component of rotation in a wide range of signal amplitude form 10–8 rad/s to 10 rad/s, as well as frequency from 0 Hz to the upper frequency from 2.56 Hz to 328.12 Hz. The laboratory investigation of our system indicated that it keeps theoretical sensitivity equal to 2·10–8 rad/s/Hz1/2 and accuracy no less than 3·1–8 to 1.6·10–6 rad/s in the above mentioned frequency band. Moreover, system size that equals 0.36×0.36×0.16 m and opportunity to remotely control the system via Internet by special server make FOSREM a mobile and autonomous device.

Go to article

Authors and Affiliations

A. Kurzych
Jerzy K. Kowalski
ORCID: ORCID
Bartosz Sakowicz
ORCID: ORCID
Z. Krajewski
L.R. Jaroszewicz
ORCID: ORCID
Download PDF Download RIS Download Bibtex

Abstract

Thin films were prepared based on cellulose polymer doped with different ratios of natural dye derived from Portulaca grandiflora concentrations. The polymer and natural dye were extracted from eco-friendly materials—the cell walls of millet husks and Portulaca grandiflora, respectively. The spray pyrolysis technique was applied to prepare thin film samples to control the film morphology and reduce the roughness of the surface. Optical microscope and Fourier transform infrared were used to analyse structural, morphological, and functional groups for all samples, respectively. The peak absorbance, extinction coefficient, optical bandgap, Urbach energy, and optical conductivity for the thin films were determined using ultraviolet-visible spectroscopy. The results show an enhancement in the optical characteristics when the natural cellulose is doped with a dye. Doping cellulose with 5% P. grandiflora has led to a considerable reduction in the energy bandgap (to 1.95 eV), compared to the sample doped with 1%.
Go to article

Authors and Affiliations

Tahseen Alaridhee
1
ORCID: ORCID
Mohammed T. Obeed
1
ORCID: ORCID
Fatima H. Malk
1
ORCID: ORCID
Baheya A. Dhahi
1

  1. Department of Material Science, Polymer Research Centre, University of Basrah, Iraq
Download PDF Download RIS Download Bibtex

Abstract

An overview of our recent developments, regarding “water-window” soft X-ray (SXR) microscopy based on a laser-plasma double stream gas puff target sources is presented. The work, presented herein, describes two approaches to SXR microscopy. The first one is a low spatial resolution, achromatic SXR microscopy, employing Wolter type-I objective. The second one is a nanometer spatial resolution SXR microscopy, with the use of a Fresnel zone plate objective, for imaging various objects with quasimonochromatic light, emitted from a double stream gas puff target based short wavelength source. The developments regarding both systems are presented, as well as the possible applications, for which the SXR microscope was already employed. Such compact, table-top size, laboratory type microscopy setups may be employed in the near future for complementary-like studies to other, often used, microscopy techniques.

Go to article

Authors and Affiliations

P.W. Wachulak
Download PDF Download RIS Download Bibtex

Abstract

In this paper we propose a method which allows to overcome the basic functional problems in holographic displays with naked eye observation caused by delivering too small images visible in narrow viewing angles. The solution is based on combining the spatiotemporal multiplexing method with a 4f optical system. It enables to increase an aperture of a holographic display and extend the angular visual field of view. The applicability of the modified display is evidenced by Wigner distribution analysis of holographic imaging with spatiotemporal multiplexing method and by the experiments performed at the display demonstrator.

Go to article

Authors and Affiliations

G. Finke
M. Kujawińska
T. Kozacki
W. Zaperty
Download PDF Download RIS Download Bibtex

Abstract

There exists a need in a quality and accuracy of a three-dimensional laser metrology operating in numerically controlled automatic machines. For this purpose, one sends three laser beams mutually perpendicular. These three beams of the wavelength λ = 0.6328 μm are generated by the same laser and are directed along three independent, orthogonal, mutually perpendicular, optical paths with a given light polarization plain. Using these beams, constituting the frame of coordinates, three independent laser rangefinders are able to determine spatial coordinates of a working tool or a workpiece. To form these optical pulses, a special refractive index matched Half-Wave Plate with nematic Liquid Crystal (LCHWP) was applied. The presented half-wave plate is based on a single Twisted Nematic (TN) cell (with the twist angle Φ = π/2) of a rather high cell gap d ~15 μm filled with a newly developed High-Birefringence Nematic Liquid Crystal Mixture (HBLCM) of optical anisotropy as high as Δn ~0.40 at λ = 0.6328 μm, where the Mauguin limit above 5.00 ~ Δnd >> λ/2 = 0.32 is fulfilled.

Go to article

Authors and Affiliations

W. Piecek
L.R. Jaroszewicz
ORCID: ORCID
E. Miszczyk
Z. Raszewski
M. Mrukiewicz
P. Perkowski
E. Nowinowski-Kruszelnicki
J. Zieliński
M. Olifierczuk
J. Kędzierski
X.W. Sun
K. Garbat
K. Kowiorski
P. Morawiak
R. Mazur
J. Tkaczyk
Download PDF Download RIS Download Bibtex

Abstract

Transport, photoluminescence, THz transmission, and optically detected cyclotron resonance studies were carried out on samples with a single modulation-doped CdTe/Cd 1-xMg xTe quantum well. THz experiments were performed at liquid helium temperatures for photon energies between about 0.5 meV and 3.5 meV. An effective mass of electron was determined to be (0.1020±0.0003)m 0. Observed photoluminescence and optically detected cyclotron resonance spectra cannot be explained within the simple model of Landau quantization of parabolic bands.
Go to article

Authors and Affiliations

Jerzy Łusakowski
1
ORCID: ORCID
Maciej Zaremba
1
Adam Siemaszko
1
Krzysztof Karpierz
1
Zbigniew Adamus
2 3
ORCID: ORCID
Tomasz Wojtowicz
4
ORCID: ORCID

  1. Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
  2. Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
  3. International Research Centre Mag Top, Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
  4. International Research Centre Mag Top, Institute of Physics, Polish Academy of Sciences, Aleja Lotników 32/46, 02-668 Warsaw, Poland
Download PDF Download RIS Download Bibtex

Abstract

The Fibre Bragg Grating (FBG) based temperature optical sensor has been designed and demonstrated. FBGs have been modelled and fabricated so as to convert the Bragg wavelength shift into the intensity domain. The main experimental setup consists of a filtering FBG and two scanning FBGs, respectively, left and right scanning FBG, whereby scanning FBGs are symmetrically located on the slopes of the filtering FBG. Such an approach allows for the modulation of power for the propagating optical signal depending on the ambient temperature at the scanning FBG location. A positive or negative change of power is determined by the spectral response of the FBG. Experimental research of the scanning FBGs’ sensitivities emphasized that the key issue is the filtering FBG. A different level of sensitivity could be achieved due to the spectral characteristic of the filtering FBG. Omitting advanced and high-cost devices, the FBG-based temperature sensor is presented. The FBG-based sensor setup could yield resolution of 1°C for the range of temperature 0.5°C to 52.5°C. The experimental study has been performed as a base for an easy-placed sensor system to monitor external parameters in real environment.

Go to article

Authors and Affiliations

M. Mądry
K. Markowski
K. Jędrzejewski
E. Bereś-Pawlik
Download PDF Download RIS Download Bibtex

Abstract

In the paper the analysis of up-conversion (UC) luminescence in 0.5Yb2O3/(0.25-1)Eu2O3 (mol.%) co-doped germanate glass and optical fibre has been investigated. Up-conversion emission of bands at 591, 616, 652, 701 nm to which correspond Eu3+: 5D07F1, 5D07F2, 5D07F3, 5D07F4 transitions, respectively was obtained as a result of cooperative energy transfer between Yb3+ and Eu3+ ions. The highest up-conversion emission (Yb3+ → Eu3+ energy transfer efficiency η = 24%) was obtained in 0.5Yb2O3/0.75Eu2O3 co-doped glass. Comparison of up-conversion and down-conversion luminescence spectra of bulk glass, glass fibre and different length double-clad optical fibre (up to 5 m) showed subtle differences in shape of the spectrum. In comparison to down – conversion emission (λexc = 405 nm) main UC luminescence band is red-shifted by 2 nm and is characterized by 5 nm greater full – width half – maximum (FWHM).

Go to article

Authors and Affiliations

M. Kochanowicz
J. Zmojda
T. Ragin
P. Miluski
P. Jelen
Download PDF Download RIS Download Bibtex

Abstract

In cyclic articles previously published we described and analysed self-organized light fibres inside a liquid crystalline (LC) cell contained photosensitive polymer (PP) layer. Such asymmetric LC cell we call a hybrid LC cell. Light fibre arises along a laser beam path directed in plane of an LC cell. It means that a laser beam is parallel to photosensitive layer. We observed the asymmetric LC cell response on an external driving field polarization. Observation has been done for an AC field first. It is the reason we decided to carry out a detailed research for a DC driving field to obtain an LC cell response step by step. The properly prepared LC cell has been built with an isolating layer and garbage ions deletion. We proved by means of a physical model, as well as a numerical simulation that LC asymmetric response strongly depends on junction barriers between PP and LC layers. New parametric model for a junction barrier on PP/LC boundary has been proposed. Such model is very useful because of lack of proper conductivity and charge carriers of band structure data on LC material.

Go to article

Authors and Affiliations

P. Moszczyński
A. Walczak
P. Marciniak
Download PDF Download RIS Download Bibtex

Abstract

The article presents an overview and a classification of X-ray detection methods. The main motivation for its preparation was the need to select a suitable and useful method for detecting signals from a currently developed miniature micro-electro-mechanical system (MEMS) X-ray source. The described methods were divided into passive and active ones, among which can be distinguished: chemical, luminescent, thermo-luminescent, gas ionization, semiconductor, and calorimetric methods. The advantages and drawbacks of each method were underlined, as well as their usefulness for the characterisation of the miniature MEMS X-ray source.
Go to article

Authors and Affiliations

Paweł Urbański 
1
ORCID: ORCID
Tomasz Grzebyk
1
ORCID: ORCID

  1. Faculty of Electronics, Photonics and Microsystems, Wrocław University of Science and Technology, ul. Janiszewskiego 11/17, 50-372 Wrocław, Poland
Download PDF Download RIS Download Bibtex

Abstract

We experimentally studied three different D-shape polymer optical fibres with an exposed core for their applications as surface plasmon resonance sensors. The first one was a conventional D-shape fibre with no microstructure while in two others the fibre core was surrounded by two rings of air holes. In one of the microstructured fibres we introduced special absorbing inclusions placed outside the microstructure to attenuate leaky modes. We compared the performance of the surface plasmon resonance sensors based on the three fibres. We showed that the fibre bending enhances the resonance in all investigated fibres. The measured sensitivity of about 610 nm/RIUfor the refractive index of glycerol solution around 1.350 is similar in all fabricated sensors. However, the spectral width of the resonance curve is significantly lower for the fibre with inclusions suppressing the leaky modes.

Go to article

Authors and Affiliations

K. Gasior
T. Martynkien
G. Wojcik
P. Mergo
W. Urbanczyk
Download PDF Download RIS Download Bibtex

Abstract

Vibration is a ubiquitous phenomenon that occurs in everyday life and people are exposed to it almost all the time. Most often, vibration is measured using electromechanical devices such as piezoelectric, piezoresistive, or capacitive accelerometers. However, attention should be paid to the limitations of such vibration sensors. They cannot operate in the presence of strong electromagnetic fields. Measurements with electromechanical devices require physical contact between the sensor and the vibrating object, which is not always possible due to the design of the sensor and device. The possibility of a non-contact vibration measurement in harsh environments is provided by the technology of interferometric fibre optic sensors. This paper reports the principle of operation, design aspects, experimentation, and performance of a Mach-Zehnder interferometric setup for the measurement of vibration frequency. There are different sensing arms implemented in the interferometer: single-mode, polarization-maintaining, and tapered optical fibre. The paper emphasises the simplicity of the set-up structure and the detection capabilities based on the interferometric sensing giving the possibility of constructing a commercial vibration sensor for all industry demands.
Go to article

Authors and Affiliations

Anna T. Kurzych
1
ORCID: ORCID
Leszek R. Jaroszewicz
1
ORCID: ORCID

  1. Institute of Technical Physics, Military University of Technology, ul. Gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland
Download PDF Download RIS Download Bibtex

Abstract

Photonic devices often use light delivered by a single-mode telecommunication fibre. However, as the diameter of the core of the optical fibre is of 10 microns, and the transverse dimensions of the photonic waveguides are usually micrometer or less, there is an issue of incompatibility. The problem may be solved by application of tapered optical fibres. For efficient light coupling, the taper should be prepared so as to create a beam of long focal length and small spot diameter in the focus. The article describes the design, fabrication and characterization of tapered optical fibres prepared with a fibre-optic fusion splicer. We modelled the tapers with FDTD method, for estimation of the influence of the tapered length and angle on the spot diameter and the focal length of an outgoing beam. We fabricated tapers from a standard single mode fibre by the Ericsson 995 PMfi- bre-optic fusion splicer. We planned the splicing technology so as to get the needed features of the beam. We planned a multistep fusion process, with optimized fusion current and fusion time. The experimental measurements of best tapered optical fibres were carried out by the knife-edge method.

Go to article

Authors and Affiliations

A. Zakrzewski
A. Pięta
S. Patela
Download PDF Download RIS Download Bibtex

Abstract

A novel all optical measurement scheme is proposed to measure wideband microwave frequencies up to 30 GHz. The proposed method is based on a four-wave mixing (FWM) approach in a semiconductor optical amplifier (SOA) of both even order side-bands generated by an unknown microwave frequency modulating an optical carrier. The optical power of a generated FWM signal depends on frequency spacing between extracted side-bands. A mathematical relation is established between FWM power and frequency of an unknown signal. A calibration curve is drawn based on the mathematical relation which predicts the unknown frequency from power withdrawn after FWM

Go to article

Authors and Affiliations

A. Kumar
V. Priye
R. Raj Singh
Download PDF Download RIS Download Bibtex

Abstract

The paper presents results of a simulation of the plasmon effect achieved between a thin precious metal layer and a biconical optical fibre taper, manufactured on a standard single mode fibre. Gold, silver and titanium were used as a metal which fulfilled a cladding function for a small diameter structure. For simulation Mode Solution software was used on which modal and frequency analyses of a wavelength were provided in the range of 800–1700 nm. A displacement of a plasmon pick in dependence of thickness of a deposited precious layer for the highest plasmon effects was observed.

Go to article

Authors and Affiliations

K.A. Stasiewicz
J.E. Moś
Download PDF Download RIS Download Bibtex

Abstract

Current advances in type-II superlattice (T2SL) research at Fraunhofer IAF are elaborated on in this paper. First, the use of metastructures for quantum efficiency (QE) enhancement in the longwave infrared (LWIR) is presented. Finite element modelling results are reported on that suggest a potential for doubling of the QE at certain wavelengths with the investigated device structure. Next, characterisation results of midwave infrared (MIWR) InAs/InAsSb T2SL nBn detectors are shown. The low, diffusion-limited dark current above 120 K and a QE of 60% are comparable to the state-of-the-art. Finally, groundwork for InAs/GaSb T2SL MWIR/LWIR dual-band detector arrays based on a back-to-back heterojunction diode device concept is presented. The dry etching technology allows for steep etch trenches and full pixel reticulation with a fill factor of about 70% at 12 µm pitch. The detector characterisation at 77 K and ±250 mV bias demonstrates the bias-switchable operation mode with dark current densities of 6.1·10−9 A/cm² in the MWIR and 5.3·10−4 A/cm² in the LWIR.
Go to article

Authors and Affiliations

Raphael Müller
1
Volker Daumer
1
Tsvetelina Hugger
1
Lutz Kirste
1
Wolfgang Luppold
1
Jasmin Niemasz
1
Robert Rehm
1
Tim Stadelmann
1
Mark Wobrock
1
Quankui Yang
1

  1. Fraunhofer Institute for Solid State Physics IAF, Tullastraße 72, 79108 Freiburg, Germany
Download PDF Download RIS Download Bibtex

Abstract

This paper presents results of the characterisation of type I GaSb/AlSb superlattices (SLs) with a thin GaSb layer and varying thicknesses of an AlSb layer. Nextnano software was utilized to obtain spectral dependence of absorption and energy band structure. A superlattice (SL) with an energy bandgap of ~ 1.0 eV and reduced mismatch value was selected for experimental investigation. SLs with single (sample A) and double (sample B) AlSb barriers and a single AlSb layer (sample C) were fabricated using molecular beam epitaxy (MBE). Optical microscopy, high-resolution X-ray diffractometry, and photoluminescence were utilized for structural and optical characterisation. The presence of satellite and interference peaks in diffraction curves confirms the high crystal quality of superlattices. Photoluminescence signal associated with the superlattice was observed only for sample B and contained three low-intensity peaks: 1.03, 1.18, and 1.25 eV. The first peak was identified as the value of the energy bandgap of the SL. Other two peaks are related to optical transitions between defect states located at the interface between the SL and the top AlSb barrier. The time-dependent changes observed in the spectral characteristics are due to a modification of the SL/AlSb interface caused by the oxidation and hydroxylation of the AlSb layer.
Go to article

Authors and Affiliations

Maciej Fokt
1 2
ORCID: ORCID
Agata Jasik 
1
ORCID: ORCID
Iwona Sankowska 
1
ORCID: ORCID
Herbert S. Mączko 
3
ORCID: ORCID
Karolina M. Paradowska 
1
ORCID: ORCID
Krzysztof Czuba
1 2
ORCID: ORCID

  1. Łukasiewicz Research Network – Institute of Microelectronics and Photonics, Aleja Lotników 32/46, 02-668 Warsaw, Poland
  2. Warsaw University of Technology, ul. Nowowiejska 15/19, 00-665 Warsaw, Poland
  3. nextnano GmbH, Konrad-Zuse-Platz 8, 81829 München, Germany
Download PDF Download RIS Download Bibtex

Abstract

A theoretical analysis of the mid-wavelength infrared range detectors based on the HgCdTe materials for high operating temperatures is presented. Numerical calculations were compared with the experimental data for HgCdTe heterostructures grown by the MOCVD on the GaAs substrates. Theoretical modelling was performed by the commercial platform SimuAPSYS (Crosslight). SimuAPSYS fully supports numerical simulations and helps understand the mechanisms occurring in the detector structures. Theoretical estimates were compared with the dark current density experimental data at the selected characteristic temperatures: 230 K and 300 K. The proper agreement between theoretical and experimental data was reached by changing Auger-1 and Auger-7 recombination rates and Shockley-Read-Hall carrier lifetime. The level of the match was confirmed by a theoretical evaluation of the current responsivity and zero-bias dynamic resistance area product (R0A) of the tested detectors.
Go to article

Bibliography

  1. Lawson, W. D., Nielson, S., Putley, E. H. & Young, A. S. Preparation and properties of HgTe and mixed crystals of HgTe-CdTe. Phys. Chem. Solids 9, 325–329 (1959). https://doi.org/10.1016/0022-3697(59)90110-6
  2. Rogalski, A. HgCdTe infrared detector material: history, status and outlook. Prog. Phys. 68, 2267–2336 (2005). https://doi.org/10.1088/0034-4885/68/10/r01
  3. Hansen, G. L., Schmit, J. L. & Casselman, T. N. Energy gap versus alloy composition and temperature in Hg1-xCdx J. Appl. Phys. 53, 7099–7101 (1982). https://doi.org/10.1063/1.330018
  4. Harman, T. C. & Strauss, J. Band structure of HgSe and HgSe-HgTe alloys. Appl. Phys. 32, 2265–2270 (1961). https://doi.org/10.1063/1.1777057
  5. Martyniuk, P. & Rogalski, A. Performance comparison of barrier detectors and HgCdTe photodiodes. Eng. 53, 106105 (2014). https://doi.org/10.1117/1.OE.53.10.106105
  6. Rogalski, A. Infrared and Terahertz Detectors. (3rd) (CRC Press Taylor & Francis Group, 2020). https://doi.org/10.1201/b21951
  7. Lei, W., Antoszewski, J. & Faraone L. Progress, challenges, and opportunities for HgCdTe infrared materials and Detectors. Phys. Rev. 2, 041303 (2015). https://doi.org/10.1063/1.4936577
  8. Norton, P. HgCdTe infrared detectors. Opto-Electron. Rev. 10, 159–174 (2002). https://optor.wat.edu.pl/10(3)159.pdf
  9. Qiu, W. C., Jiang, T. & Cheng, X. A. A bandgap-engineered HgCdTe PBπn long-wavelength infrared detector. Appl. Phys. 118, 124504 (2015). https://doi.org/10.1063/1.4931661
  10. Iakovleva, N. I. The study of dark currents in HgCdTe hetero-structure photodiodes. Commun. Technol. Electron. 66, 368–374 (2021). https://doi.org/10.1134/S1064226921030220
  11. Martyniuk, P. & Rogalski, A. HOT infrared photodetectors. Opto-Electron. Rev. 21, 240–258 (2013). https://doi.org/10.2478/s11772-013-0090-x
  12. Piotrowski, J. & Rogalski, A. Uncooled long wavelength infrared photon detectors. Infrared Phys. Technol. 46, 115–131 (2004). https://doi.org/10.1016/j.infrared.2004.03.016
  13. Elliott, C. T. Non-equilibrium mode of operation of narrow-gap semiconductor devices. Sci. Technol. 5, S30–S37 (1990). https://doi.org/10.1088/0268-1242/5/3S/008
  14. Maimon, S. & Wicks, G. nBn detector, an infrared detector with reduced dark current and higher operating temperature. Phys. Lett. 89, 151109 (2006). https://doi.org/10.1063/1.2360235
  15. Kopytko, M., Kębłowski , A., Gawron, W. & Pusz, LWIR HgCdTe barrier photodiode with Auger-suppression. Semicond. Sci. Technol. 31, 035025 (2016). https://doi.org/10.1088/0268-1242/31/3/035025
  16. He, J. et al. Design of a bandgap-engineered barrier-blocking HOT HgCdTe long-wavelength infrared avalanche photodiode. Express 28, 33556 (2020). https://doi.org/10.1364/OE.408526
  17. Gawron, W. et al. MOCVD Grown HgCdTe heterostructures for medium wave infrared detectors. Coatings 11, 611 (2021). https://doi.org/10.3390/coatings11050611
  18. Kębłowski, A. et al. Progress in MOCVD growth of HgCdTe epilayers for HOT infrared detectors. SPIE. 9819, 98191E-1 (2016). https://doi.org/10.1117/12.2229077
  19. APSYS Macro/User’s Manual ver. 2011. Crosslight Software, Inc. (2011).
  20. Capper, P. P. Properties of Narrow Gap Cadmium-Based Compounds. (INSPEC, the Institution of Electrical Engineers, 1994).
  21. Long, F. et al. The structural dependence of the effective mass and Luttinger parameters in semiconductor quantum wells. Appl. Phys. 82, 3414–3421 (1997). https://doi.org/10.1063/1.365657
  22. Lopes, V. C., Syllaios, A. J. & Chen, M. C. Minority carrier lifetime in mercury cadmium telluride. Sci. Technol. 8, 824–841 (1993). https://doi.org/10.1088/0268-1242/8/6s/005
  23. Aleshkin, V.Y. et al. Auger recombination in narrow gap HgCdTe/CdHgTe quantum well heterostructures. Appl. Phys. 129, 133106 (2021). https://doi.org/10.1063/5.0046983
  24. Reine, M. B. et al. HgCdTe MWIR back-illuminated electron-initiated avalanche photodiode arrays. Electron. 36, 1059–1067 (2007). https://doi.org/10.1007/s11664-007-0172-y
  25. Schuster, J. et al. Junction optimization in HgCdTe: Shockley-Read-Hall generation-recombination suppression. Phys. Lett. 107, 023502 (2015). https://doi.org/10.1063/1.4926603
  26. Schacham, S. E. & Finkman, E. Recombination mechanisms in p-type HgCdTe: Freezeout and background flux effects. Appl. Phys. 57, 2001–2009 (1985). https://doi.org/10.1063/1.334386
  27. Zhu, L. et al. Temperature-dependent characteristics of HgCdTe mid-wave infrared e-avalanche photodiode. IEEE J. Sel. Top. Quantum Electron. 28, 3802709 (2022). https://doi.org/10.1109/JSTQE.2021.3121273
  28. Kopytko, M., Jóźwikowski, K., Martyniuk, P. & Rogalski, A. Photon recycling effect in small poxel p-i-n HgCdTe long wavelenght infrared photodiodes. Infrared Phys. Technol. 97, 38–42 (2019). https://doi.org/10.1016/j.infrared.2018.12.015
  29. Olson, B. V. et al. Auger recombination in long-wave infrared InAs/InAsSb type-II superlattices. Phys. Lett. 107, 261104 (2015). https://doi.org/10.1063/1.4939147
  30. Beattie, A. R. & Landsberg, P. Auger effect in semiconductors. Proc. Math. Phys. Eng. Sci. A249, 16−29 1959. https://doi.org/10.1098/rspa.1959.0003
  31. Krishnaumurthy, S. & Casselman, T. N. A detailed calculation of the Auger lifetime in p-type HgCdTe. Electron. Mater. 29, 828−831 (2000). https://doi.org/10.1007/s11664-000-0232-z
Go to article

Authors and Affiliations

Tetiana Manyk
1
ORCID: ORCID
Jarosław Rutkowski
1
ORCID: ORCID
Paweł Madejczyk
1
ORCID: ORCID
Waldemar Gawron
1 2
ORCID: ORCID
Piotr Martyniuk
1
ORCID: ORCID

  1. Institute of Applied Physics, Military University of Technology, 2. Kaliskiego St., 00-908 Warsaw, Poland
  2. VIGO System S.A., 129/133 Poznańska St., 05-850 Ożarów Mazowiecki, Poland
Download PDF Download RIS Download Bibtex

Abstract

Hybrid pixel radiation detectors with a direct photon-to-charge conversion working in a single photon counting mode have gained increasing attention due to their high dynamic range and noiseless imaging. Since sensors of different materials can be attached to readout electronics, they enable work with a wide range of photon energies. The charge-sharing effect observed in segmented devices, such as hybrid pixel detectors, is a phenomenon that deteriorates both spatial resolution and detection efficiency. Algorithms that allow the detection of a photon irrespective of the charge-sharing effect are proposed to overcome these limitations. However, the spatial resolution of the detector can be further improved beyond the resolution determined by the pixel size if information about the charge proportions collected by neighbouring pixels is used to approximate the interaction position. In the article, an approach to achieve a subpixel resolution in a hybrid pixel detector working in the single photon counting mode is described. Requirements and limitations of digital inter-pixel algorithms which can be implemented on-chip are studied. In the simulations, the factors influencing the detector resolution are evaluated, including size of a charge cloud, number of virtual pixel subdivisions, and detector parameters.
Go to article

Bibliography

  1. Ballabriga, et al. Review of hybrid pixel detector readout ASICs for spectroscopic X-ray imaging. J. Instrum. 11, P01007–P01007 (2016). https://doi.org/10.1088/1748-0221/11/01/P01007
  2. Taguchi, K. & Iwanczyk, J. S. Vision 20/20: Single photon counting X-ray detectors in medical imaging. Med. Phys. 40, 100901 (2013). https://doi.org/10.1118/1.4820371
  3. Bahadur, D. et al. Evolution of structure and dynamics of thermo-reversible nanoparticle gels-A combined XPCS and rheology study. J. Chem. Phys. 151, 10 (2019). https://doi.org/10.1063/1.5111521
  4. Sheyfer, et al.Nanoscale critical phenomena in a complex fluid studied by X-ray photon correlation spectroscopy.Phys. Rev. Lett. 125, 125504 (2020). https://doi.org/10.1103/PhysRevLett.125.125504
  5. Szczygiel, R., Grybos, P., Maj, P. & Zoladz, M. PXD18k - Fast Single Photon Counting Chip with Energy Window for Hybrid Pixel Detector. in 2011 IEEE Nuclear Science Symposium Conference Record. 932–937 (IEEE, Valencia, Spain 2011). https://doi.org/10.1109/NSSMIC.2011.6154126
  6. Nilsson, H. E., Dubari, E., Hjelm, M. & Bertilsson, K. Simulation of photon and charge transport in x-ray imaging semiconductor sensors. Nucl. Instrum. Methods Phys. Res. A. 487, 151–162 (2002). https://doi.org/10.1016/S0168- 9002(02)00959-2
  7. Ballabriga, R. et al. The Medipix3RX: a high resolution, zero dead-time pixel detector readout chip allowing spectroscopic imaging. Instrum. 8, C02016–C02016 (2013). https://doi.org/10.1088/1748-0221/8/02/C02016
  8. Krzyzanowska, A. et al. Characterization of the photon counting CHASE Jr., chip built in a 40-nm CMOS process with a charge-sharing correction algorithm using a collimated X-ray beam. IEEE Trans. Nucl. Sci. 64, 2561–2568 (2017). https://doi.org/10.1109/TNS.2017.2734821
  9. Bellazzini, R. et al. PIXIE III: a very large area photon-counting CMOS pixel ASIC for sharp X-ray spectral imaging. J. Instrum. 10, C01032–C01032 (2015). https://doi.org/10.1088/1748-0221/10/01/C01032
  10. Otfinowski, P. et al. Comparison of allocation algorithms for unambiguous registration of hits in presence of charge- sharing in pixel detectors. J. Instrum. 12, C01027–C01027 (2017). http://doi.org/10.1088/1748-0221/12/01/C01027
  11. Otfinowski, P., Deptuch, G. W. & Maj, P. Asynchronous approximation of a center of gravity for pixel detectors’ readout circuits. IEEE Solid-State Circuits 53, 1550–1558 (2018). https://doi.org/10.1109/JSSC.2018.2793530
  12. Cartier, et al. Micron resolution of MÖNCH and GOTTHARD, small pitch charge integrating detectors with single photon sensitivity. J. Instrum. 9, C05027–C05027 (2014). https://doi.org/10.1088/1748-0221/9/05/C05027
  13. Dreier, E. S. et al. Virtual subpixel approach for single-mask phase-contrast imaging using Timepix3. J. Instrum. 14, C01011 (2019). https://doi.org/10.1088/1748-0221/14/01/C01011
  14. Maj, P. et al. Measurements of ultra-fast single photon counting chip with energy window and 75 μm pixel pitch with Si and CdTe J. Instrum. 12, C03064 (2017). https://doi.org/10.1088/1748-0221/12/03/C03064
  15. Krzyzanowska, A., Niedzielska, A. & Szczygieł, R. Charge-sharing simulations for new digital algorithms achieving subpixel resolution in hybrid pixel detectors. J. Instrum. 15, C02047 (2020). https://doi.org/10.1088/1748- 0221/15/02/C02047
  16. Lutz, Semiconductor Radiation Detectors, Device Physics. (Berlin, Heidelberg: Springer Berlin Heidelberg, 2007).
  17. NIST XCOM: Photon Cross Sections Database – Introduction. NIST http://www.physics.nist.gov/PhysRefData/Xcom/Text/intro.html (2017).
  18. Otfinowski, A. et al. Pattern recognition algorithm for charge-sharing compensation in single photon counting pixel detectors. J. Instrum. 14, C01017 (2019). https://doi.org/10.1088/1748-0221/14/01/C01017
Go to article

Authors and Affiliations

Aleksandra Krzyżanowska
1
ORCID: ORCID
Robert Szczygieł
1
ORCID: ORCID

  1. AGH University of Science and Technology, 30 A. Mickiewicza Ave., 30-059 Krakow, Poland
Download PDF Download RIS Download Bibtex

Abstract

Non−uniformity noise, it was, it is, and it will probably be one of the most non−desired attached companion of the infrared focal plane array (IRFPA) data. We present a higher order filter where the key advantage is based in its capacity to estimates the detection parameters and thus to compensate it for fixed pattern noise, as an enhancement of Constant Statistics (CS) theory. This paper shows a technique to improve the convergence in accelerated way for CS (AACS: Acceleration Algorithm for Constant Statistics). The effectiveness of this method is demonstrated by using simulated infrared video sequences and several real infrared video sequences obtained using two infrared cameras

Go to article

Authors and Affiliations

A.G. Jara-Chavez
F.O. Torres-Vicencio
Download PDF Download RIS Download Bibtex

Abstract

The subflorescence and efflorescence phenomena are widely acknowledged as the major causes of permanent damage to fresco wall paintings. They are related to the occurrence of cycles of dry/wet conditions inside the walls. Therefore, it is essential to identify the presence of water on the decorated surfaces and inside the walls.

Nondestructive testing in industrial applications have confirmed that active infrared thermography with continuous timed images acquisition can improve the outcomes of thermal analysis aimed to moisture identification. In spite of that, in cultural heritage investigations these techniques have not been yet used extensively on a regular basis. This paper illustrates an application of these principles in order to evaluate the decay of fresco mural paintings in a medieval chapel located in North−West of Italy. One important feature of this study is the use of a robotic system called aIRview that can be utilized to automatically acquire and process thermal images. Multiple accurate thermal views of the inside walls of the building have been produced in a survey that lasted several days. Signal processing algorithms based on Fast Fourier Transform analysis have been applied to the acquired data in order to formulate trustworthy hypotheses about the deterioration mechanisms.

Go to article

Authors and Affiliations

G. Cadelano
P. Bison
A. Bortolin
G. Ferrarini
F. Peron
M. Girotto
M. Volinia
Download PDF Download RIS Download Bibtex

Abstract

This paper presents and assesses an inverse heat conduction problem (IHCP) solution procedure which was developed to determine the local convective heat transfer coefficient along the circumferential coordinate at the inner wall of a coiled pipe by applying the filtering technique approach to infrared temperature maps acquired on the outer tube’s wall. The data−processing procedure filters out the unwanted noise from the raw temperature data to enable the direct calculation of its Laplacian which is embedded in the formulation of the inverse heat conduction problem. The presented technique is experimentally verified using data that were acquired in the laminar flow regime that is frequently found in coiled−tube heat−exchanger applications. The estimated convective heat transfer coefficient distributions are substantially consistent with the available numerical results in the scientific literature.

Go to article

Authors and Affiliations

F. Bozzoli
L. Cattani
G. Pagliarini
S. Rainieri

This page uses 'cookies'. Learn more