Journals >Journal of Infrared and Millimeter Waves
Contents
2005
Volume: 24 Issue 2
18 Article(s)
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Research Article
P-TYPE ACTIVATION RESEARCH OF As-DOPING IN MBE HgCdTe FILMS
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The study on As 4-doped HgCdTe epilayers grown by MBE was presented. The electrical activation of arsenic impurities was achieved by annealing that caused As to occupy Te sites. By using the secondary ion mass spectrometry (SIMS) and Hall measurements on the in situ arsenic doped HgCdTe epilayers, the results show thatThe study on As 4-doped HgCdTe epilayers grown by MBE was presented. The electrical activation of arsenic impurities was achieved by annealing that caused As to occupy Te sites. By using the secondary ion mass spectrometry (SIMS) and Hall measurements on the in situ arsenic doped HgCdTe epilayers, the results show that P-type MBE HgCdTe can be obtained by doping with As 4 source and annealing with high temperature..
Journal of Infrared and Millimeter Waves
- Publication Date: Jan. 01, 1900
- Vol. 24, Issue 2, 81 (2005)
INVESTIGATION OF PHTOLUMINESECENCE UNDER HYDROSTATIC PRESSURE IN DIFFERENT SIZED ZnS:Mn NANOPARTICLES
[in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The PL spectra for the 10, 4.5, 3.5, 3,1nm sized ZnS:Mn~2+ nanoparticles and corresponding bulk material under different pressures were investigated. The orange emission band originated from the 4T 1-6A 1 transition of Mn~2+ ions showed obvious red shift with the increasing of pressures. The pressure coefficients of MnThe PL spectra for the 10, 4.5, 3.5, 3,1nm sized ZnS:Mn~2+ nanoparticles and corresponding bulk material under different pressures were investigated. The orange emission band originated from the 4T 1-6A 1 transition of Mn~2+ ions showed obvious red shift with the increasing of pressures. The pressure coefficients of Mn-related emissions measured from bulk, 10, 4.5, 3.5 and 3nm samples are -29.4±0.3, -30.1±0.3, -33.3±0.6, -34.6±0.8 and -39±1 meV/GPa, respectively. The absolute value of the pressure coefficient increases with the decrease of the size of particles. The size dependence of crystal field strength Dq and Racah parameter B accounts for the size behavior of the Mn-related emission in ZnS:Mn nanoparticles. The pressure behavior of Mn-related emission in the 1 nm sized sample is somewhat different from that of other nanoparticles. It may be due to smaller size of 1 nm sample and the special surface condition since ZnS nanoparticles are formed in the cavities of ziolite-Y for the 1 nm sample..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 84 (2005)
TEMPERATURE DEPENDENCE OF THE SELF-TRAPPING ENERGY OF STRONG-COUPLING POLARON IN A QUANTUM WELL
[in Chinese]
The effects of lattice vibration on the properties of the polaron, which was weakly coupled with bulk longitudinal optical phonons and strongly coupled interface optical phonons, in an infinite quantum well were studied by means of the Huybrechts’ linear-combination operator and a modified LLP variational method . The The effects of lattice vibration on the properties of the polaron, which was weakly coupled with bulk longitudinal optical phonons and strongly coupled interface optical phonons, in an infinite quantum well were studied by means of the Huybrechts’ linear-combination operator and a modified LLP variational method . The expressions for the self-trapping energy of the polaron in a quantum well as a function of the well’s width and temperature were derived. Numerical results of the polaron self-trapping energy for KI/AgCl/KI QW show that the self-trapping energy of the polaron will decrease with increasing the well’s width and temperature, but the contribution of interaction between the electron and the different branch of phonons to the self-trapping energy and their changing with the well’s width and temperature are different..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 89 (2005)
INFLUENCE OF OXYGEN CONTENT ON THE PROPERTIES OF CRYSTAL LATTICE AND PHASE TRANSITION IN VO2-x NANOPOWDERS
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
VO2-x nanopowders were successfully synthesized with different oxygen content. The effects of oxygen content on the crystal lattice and phase transition properties were obtained form the experiment. Our result shows that vanadium interstitials are formed in oxygen-deficient samples, while oxygen interstitials are formeVO2-x nanopowders were successfully synthesized with different oxygen content. The effects of oxygen content on the crystal lattice and phase transition properties were obtained form the experiment. Our result shows that vanadium interstitials are formed in oxygen-deficient samples, while oxygen interstitials are formed in the samples with excess oxygen. Both factors result in the expansion of the volume in the crystal unit cell. And the defects induce anisotropy in the lattice, which is observed in the deformation of the crystal grains with different oxygen content. The redistribution of electronic strucure in the energy band may be one of the factors that result in the changes of phase transition properties in VO2-x..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 93 (2005)
MEASUREMENT OF RESPONSE PEAK WAVELENGTH OF QUANTUM WELL INFRARED DETECTORS BY RAMAN SCATTERING
[in Chinese], [in Chinese], [in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The response peak wavelength of a quantum well infrared detector was predicted directly by measuring Raman spectrum of multiquantum well materials. It no longer requires preparing infrared detector or polishing on the edge of sample. Therefore, this method is simple and reliable.The response peak wavelength of a quantum well infrared detector was predicted directly by measuring Raman spectrum of multiquantum well materials. It no longer requires preparing infrared detector or polishing on the edge of sample. Therefore, this method is simple and reliable..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 97 (2005)
SIMULATION OF INFRARED RADIATION CHARACTERISTICS OF HIGH TEMPERATURE FREE-STREAM FLOW INCLUDING PARTICLES BY USING BACKWARD MONTE-CARLO METHOD
[in Chinese], [in Chinese], and [in Chinese]
The research of infrared radiation characteristics of high temperature free-stream flow with particles is very important for the field of target detection, combustion diagnosis and temperature measurement of flame. In this study the infrared radiation characteristics of high temperature free-stream flow were calculatedThe research of infrared radiation characteristics of high temperature free-stream flow with particles is very important for the field of target detection, combustion diagnosis and temperature measurement of flame. In this study the infrared radiation characteristics of high temperature free-stream flow were calculated with backward Monte-Carlo method. The effect of the particle scattering and different boundary conditions on the directional radiation heat flux was examined. The calculation results were compared with forward Monte-Carlo method. The result shows the superiority in computational efficiency of backward Monte-Carlo method..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 100 (2005)
EFFECT OF INTERFACE AND SURFACE ADHENSION LAYERS ON PHASE SHIFT OF OPTICAL COATINGS
[in Chinese], [in Chinese], and [in Chinese]
When incoming light beam enters dielectric reflective mirror with a certain incident angle, there will be a phase shift between the p-polarization and s-polarization. The theoretical model for adhesion layer of interface and surface was established based on the real conditions of interface between layer and atmosphere,When incoming light beam enters dielectric reflective mirror with a certain incident angle, there will be a phase shift between the p-polarization and s-polarization. The theoretical model for adhesion layer of interface and surface was established based on the real conditions of interface between layer and atmosphere, and between two neighboring layers. At the same time, this model was used to explain the reason for error of phase shift. Based on optimizing design, when light enters with 54 degree, the phase shift of 270±1° was obtained in the range of 1285~1345nm, meantime, the reflectivity of dielectric mirror maintained over 99.5%. The phase retarder film was prepared with dual ion beam sputter system. The spectrum and the phase of the sample were gained by spectrometer and the Fourier transform infrared spectroscopic ellipsomter, respectively. The results reveal that the samples have phase shift of 262.4±1.8° and the reflectivity reaches over 99.6%. The error mainly originates from non-homogeneous transi.
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 105 (2005)
ANISOTROPIC GAUSSIAN FILTERING FOR INFRARED IMAGE
[in Chinese], [in Chinese], and [in Chinese]
To achieve much better noise suppression with minimum edge blurring, an adaptive anisotropic gaussian filtering algorithm was proposed. In this algorthm, the scale of filter’s long axes was determined by Intensity-Dependent-Spread model in each pixel, and the ratio between filter’s long axes and short axes was determinTo achieve much better noise suppression with minimum edge blurring, an adaptive anisotropic gaussian filtering algorithm was proposed. In this algorthm, the scale of filter’s long axes was determined by Intensity-Dependent-Spread model in each pixel, and the ratio between filter’s long axes and short axes was determined by the degree of local smoothness, then the orientation of the filter’s long axes was also calculated according to the gray gradient orientation in the position. The experimental result shows that the algorithm has good capability in noise suppression and edge-preserving..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 109 (2005)
REAL-TIME SEGMENTATION TECHNOLOGY OF MAN-MADE INFRARED OBJECT BASED ON NORMALIZED CUTS
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
An effective aproach based on normalized cuts to segment infrared object was presented. The method is related to the graph theory. An image was represented as a weighted undirected graph, where the nodes of the graph were the pixels of the image, and an edge was formed between every pair of pixels. The weight on each eAn effective aproach based on normalized cuts to segment infrared object was presented. The method is related to the graph theory. An image was represented as a weighted undirected graph, where the nodes of the graph were the pixels of the image, and an edge was formed between every pair of pixels. The weight on each edge was function of the similarity between the two pixels, and the similarity was related to the gray level and the position of pixels. Normalized cut was chosen as the principle to distingusish object from background. The time and space complexity of the algorithm was studied. Four kinds of domain-weight-matrix were defined and a quick table-search method was presented to improve the real-time algorithm. The experimental results show that the proposed method has excellence performance, and it is superior to the traditional segmentation method..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 114 (2005)
NEW APPROACH OF IRFPA NON-EFFECTIVE PIXEL DISCRIMINATION BASED ON PIXEL'S CHARACTERISTICS HISTOGRAM ANALYSIS
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
A new approach of IRFPA non-effective pixel discrimination based on pixel′s two kinds of characteristic histogram decomposition was presented. Based on the analysis of the model for the effective pixel response, the approach proposes that, if the incident flux is uniform, the standard deviation(STD) and the difference A new approach of IRFPA non-effective pixel discrimination based on pixel′s two kinds of characteristic histogram decomposition was presented. Based on the analysis of the model for the effective pixel response, the approach proposes that, if the incident flux is uniform, the standard deviation(STD) and the difference of two means(DOM) for all effective pixels are both normal distributed random variables. By decomposing STD and DOM histograms through adaptive projective decomposition, the DOM and STD distribution range of effective pixel then can be estimated, and the discrimination rule for non-effective pixel is got ultimately. The experiment result using real infrared image shows the proposed technique for IRFPA non-effective pixel discrimination is effective and feasible..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 119 (2005)
MODEL EXPERIMENTS OF INFRARED SUPPRESSOR FOR HELICOPTER EXHAUST SYSTEM
[in Chinese], [in Chinese], and [in Chinese]
A series of mode experiments for the infrared signature suppression (IRSS) device used in the helicopter gas turbine exhaust system were carried out to investigate the effects of ambient air pumping-mixing and heat shelter-insulation on decreasing the target infrared signature and quest for the infrared signature similA series of mode experiments for the infrared signature suppression (IRSS) device used in the helicopter gas turbine exhaust system were carried out to investigate the effects of ambient air pumping-mixing and heat shelter-insulation on decreasing the target infrared signature and quest for the infrared signature similarity between two scaled models with different scale factors. The results show that (1) Ambient air pumping-mixing plays a dual role for reducing the exhaust temperature and mixing duct temperature and this role is more obvious in the case of larger mass flow ratio of secondary flow to primary flow. Sheltering from the hot mixing duct wall makes the sheltering sheath temperature close to ambient temperature in case of the sheltering distance greater than 20mm. (2) Ambient air pumping-mixing contributes about 85% suppression for the total target infrared radiation intensity and heat shelter-insulation contributes about 10% suppression again. (3) While the primary flow velocity, temperature and pressure are at the same condition intensity is almost proportion to the square of model scale factor..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 125 (2005)
REGULARIZED RESTORATION ALGORITHM OF ASTRONAUTCAL TURBULENCE-DEGRADED IMAGES USING MAXIMUM-LIKELIHOOD ESTIMATION
[in Chinese], [in Chinese], and [in Chinese]
A regularized restoration algorithm based on maximum-likelihood estimation was presented for restoring object images from the noisy turbulence-degraded images. The logarithmic maximum-likelihood function for multi-frame image data based on the model of image random field was built, and some auxiliary terms to smooth noA regularized restoration algorithm based on maximum-likelihood estimation was presented for restoring object images from the noisy turbulence-degraded images. The logarithmic maximum-likelihood function for multi-frame image data based on the model of image random field was built, and some auxiliary terms to smooth noise while preserve the edges of images and the penalized item to avoid trivial solutions were added to the maximum-likelihood function. The iterative formulas of calculating the PSFs and object image were derived so that the PSFs and the object image could be estimated in the iterative manner. A parallel processing scheme for the algorithm is also proposed.The restoration experiments on the simulated turbulence-degraded images in the case of noise show that the proposed algorithm has high ability of noise-resisting and it has some practical applications..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 130 (2005)
IMAGE RETRIEVAL BASED ON IMAGE ENTROPY AND SPATIAL DISTRIBUTION ENTROPY
[in Chinese], [in Chinese], and [in Chinese]
A new image retrieval algorithm based on image entropy and spatial distribution entropy was presented. At first a more robust method, which can remove the influence of the symmetry of entropy, was proposed to extract the global color feature. Then color spatial distribution entropy vector for each color channel was alsA new image retrieval algorithm based on image entropy and spatial distribution entropy was presented. At first a more robust method, which can remove the influence of the symmetry of entropy, was proposed to extract the global color feature. Then color spatial distribution entropy vector for each color channel was also introduced to represent the spatial color information. After that, the moments were adopted to reduce the dimension of color spatial distribution entropy. In the end, a low dimensional vector which includes the global and spatial information was used as index for color image retrieval. The experiment results show that the new method gives better performance than color histogram..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 135 (2005)
STUDY ON THE MINORITY CARRIER DIFFUSION CHARACTERISTIC OF HgCdTe DIODES BY I-V MEASUREMENT IN A VARIATIONAL MAGNETIC FIELD
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
The zero-bias resistance area product (R 0A) and the saturation current density J 0 are both key parameters to give an indication of photodiode performance. In this study, an effectual experimental method to study the minority carrier diffusion characteristics of Hg ~1-xCd xTe photodiodes was presented. By I-V tests inThe zero-bias resistance area product (R 0A) and the saturation current density J 0 are both key parameters to give an indication of photodiode performance. In this study, an effectual experimental method to study the minority carrier diffusion characteristics of Hg ~1-xCd xTe photodiodes was presented. By I-V tests in a variational magnetic field B, R 0A and J 0 measurements were carried out as a function of B in the alloy composition range 0.5 < x < 0. 6. Based on the test results,the minority carrier diffusion length of shortwavelength infrared ( SW IR) HgCdTe photodiodes operating at room temperature was calculated. The value is in agreementwith the scale measured by laser beam induced current (LB IC)method..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 140 (2005)
FABRICATION OF ARRAYED WAVEGUIDE GRATING BASED ON SOI MATERIAL
[in Chinese], [in Chinese], and [in Chinese]
An arrayed waveguide grating based on SOI material was fabricated by inductive coupled plasma (ICP) etching technology. The central wavelength of the device was designed at 1.5509μm and the channel spacing was 200GHz. Comparing with the values of the design, the differences of the central wavelength and the channel spaAn arrayed waveguide grating based on SOI material was fabricated by inductive coupled plasma (ICP) etching technology. The central wavelength of the device was designed at 1.5509μm and the channel spacing was 200GHz. Comparing with the values of the design, the differences of the central wavelength and the channel spacing in the test were ~0.28nm and 0.02nm, respectively. The adjacent channel crosstalk was about 10dB, and the uniformity of the five channels’ insertion loss was only 0.7 dB. The results show that the device can be used as a demultiplexer..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 143 (2005)
NOVEL METHOD OF DETECTING FOREIGN FIBERS IN LINT BY FIBER'S INFRARED ABSORPTION CHARACTERISTIC
[in Chinese], and [in Chinese]
For effective detection of foreign fibers which have almost the same shape and color as the cotton fibers, an infrared spectral imaging method based on the absorption characteristic discrimination between cotton fibers and foreign fibers was proposed. According to the method, the relation between the absorption charactFor effective detection of foreign fibers which have almost the same shape and color as the cotton fibers, an infrared spectral imaging method based on the absorption characteristic discrimination between cotton fibers and foreign fibers was proposed. According to the method, the relation between the absorption characteristic discrimination and the wavelength in the region of near infrared was analyzed, and the optimal band for discriminating several types of foreign fibers from cotton fibers was determined. The absorption characteristic of foreign fibers was transformed into the image feature in the infrared spectral imaging system. Furthermore, the foreign fibers were extracted form the background of lint by using adaptive image enhancement and binary image processing. The experimental result indicates that the image features of foreign fibers are obvious. And it provides an effective method to detect foreign fibers in lint..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 147 (2005)
METHOD OF INFRARED IMAGE DENOISING BASED ON STATIONARY MULTIWAVELET TRANSFORM
[in Chinese], [in Chinese], and [in Chinese]
A novel stationary multiwavelet transform (SMWT) method was proposed. The method possesses the good quality of both multiwavelet transform and stationary scalar wavelet on signal denoising. The mallat decompositing and reconstructing of 2D image based on SMWT was inferred. By thresholding the SMWT coefficients of noisyA novel stationary multiwavelet transform (SMWT) method was proposed. The method possesses the good quality of both multiwavelet transform and stationary scalar wavelet on signal denoising. The mallat decompositing and reconstructing of 2D image based on SMWT was inferred. By thresholding the SMWT coefficients of noisy infrared image, the original image can be reconstructed. The simulation results show that the image denoising effect of this method has obvious superiority compared with scalar wavelet and general multiwavelet transform method. At the same time, the reconstructing image can preserve the characterisics of original image as many as possible..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 151 (2005)
ANALYSIS OF CHARACTERISTICS ON WAVE PROPAGATION IN DIELECTRIC WAVEGUIDE ARRAY
[in Chinese], [in Chinese], [in Chinese], and [in Chinese]
Based on the presented rigorous theory for two-dimensionally periodic (2DP) medium, characteristics of wave propagation in DWA were analyzed and studied in detail. Firstly, if there existed longitudinal wave vectr (k z≠0), the characteristics of interactions between space harmonics were analyzed, and dispersion relatioBased on the presented rigorous theory for two-dimensionally periodic (2DP) medium, characteristics of wave propagation in DWA were analyzed and studied in detail. Firstly, if there existed longitudinal wave vectr (k z≠0), the characteristics of interactions between space harmonics were analyzed, and dispersion relations between transversal wave vectors were obtained. Secondly, supposing transversal wave vectors were identical (k x=k y), the characteristics of interactions between space harmonics and stop-bands caused by them were studied comprehensively, and dispersion relations between longitudinal and transversal wave vectors were also analyzed and calculated when wave frequency varied. A very interesting conclusion of purely longitudinal propagation in DWA was obtained. The results have practical application values..
Journal of Infrared and Millimeter Waves
- Publication Date: Apr. 01, 2005
- Vol. 24, Issue 2, 156 (2005)
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