• Journal of the Semiconductor & Display Technology
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• v.17 no.2
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• pp.12-15
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• 2018

InSb (III-V compound semiconductor) is used for photodiode to detect the mid-wavelength infrared radiation. Generally the quantum efficiency of InSb IR FPAs(Focal Plane Arrays) is known to be determined by thickness of InSb and transmittance of anti-reflection coating layer. In this study, we confirmed that the C-V characteristics of detector array affects the quantum efficiency of the InSb IR FPAs. We fabricated the IR FPAs with various $V_{fb}$(flat band voltage) values and confirmed the tendency between the $V_{fb}$ value and quantum efficiency of the IR FPAs.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.9
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• pp.49-56
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• 2004

A new readout circuit(ROIC) for linear HgCdTe 64${\times}$2 two-color Infrared (IR) detector is described. This circuit is based on the buffered direct injection(BDI) technology with high injection efficiency. By using saturation current isolation circuit, the proposed ROIC removed the problems that LWIR(Long Wavelength InfraRed) signal distort when MWIR(Middle Wavelength InfraRed) signal saturates so that new ROIC has larger measurable temperature range about 120k than that of previous circuit and it is also tolerant for dead pixel in MWIR detector. The designed circuit was fabricated using 0.6um 2-poly 3-metal CMOS process. We measured that the designed circuit outputs MWIR signal and LWIR signal simultaneously and saturation current isolationcircuit also operates well. Next, measured noise was about 53uV at room temperature and it can be assumed that designed circuit can satisfy nearly 95% BLIP condition at 77K.

• Journal of the Korea Convergence Society
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• v.9 no.6
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• pp.203-207
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• 2018

This paper deals with the design and development of a lens system capable of imaging an infrared image of $3{\sim}5{\mu}m$ wavelength bands with a focal length of 24mm and good atmospheric transmission characteristics. The design used CodeV, a commercial design program, and the optimization is carried out with weighting to eliminate chromatic aberration, spherical aberration and distortion. The designed lens system consists of two lenses consisting of Si and Ge. Each lens has an aspherical surface on one side. And this optical system has the resolution of the characteristics that the MTF value is 0.40 at the line width of 29lp/mm and the MTF value is 0.25 at the line width of 20lp/mm. This optical system is considered to have the capability to be applied to the thermal imaging camera for MWIR using the $206{\times}156$ array infrared detector of $25{\mu}m$ pixels and the $320{\times}240$ array infrared detector of $17{\mu}m$ pixels.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.5
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• pp.93-97
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• 2022

Infrared scenes usually contain also spectral information which cannot be resolved using normal single-band infrared cameras. Multispectral infrared imaging cameras give access to the comprehensive information contained within infrared scenes. A Dual-band infrared Camera, a type of multispectral infrared imaging cameras, has the advantage of simple system. A Dual-band Infrared Camera gives access to the spectral information as wells as the temperature information within infrared scenes. Multispectral imaging generally increases the detection and identification performance of a Dual-band Infrared Camera. This paper describes a design of an infrared Camera using a Dual-band Infrared Detector to simultaneously receive infrared radiation from the medium-wave infrared/long-wave infrared(MWIR/LWIR) bands.

• Korean Journal of Optics and Photonics
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• v.33 no.4
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• pp.146-158
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• 2022

The detector of a focal-plane-array mid-wave infrared (MWIR) camera has different response characteristics for each detector pixel, resulting in nonuniformity between detector pixels. In addition, image nonuniformity occurs due to heat generation inside the camera during operation. To solve this problem, in the process of camera manufacturing it is common to use a gain-and-offset table generated from a blackbody to correct the difference between detector pixels. One method of correcting nonuniformity due to internal heat generation during the operation of the camera generates a new offset value based on input frame images. This paper proposes a technique for dividing an input image into block image patches and generating offset values using only homogeneous patches, to correct the nonuniformity that occurs during camera operation. The proposed technique may not only generate a nonuniformity-correction offset that can prevent motion marks due to camera-gaze movement of the acquired image, but may also improve nonuniformity-correction performance with a small number of input images. Experimental results show that distortion such as flow marks does not occur, and good correction performance can be confirmed even with half the number of input images or fewer, compared to the traditional method.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.3
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• pp.63-71
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• 2000

Infrared (IR) detector chip, which detects the IR radiation from all of the objects and converts to image signal, is usually fabricated using hybrid bonding technology with detector away and readout integrated circuit (ROIC). In this study, we designed the readout circuit and simulated its operations. Fabricating readout circuit chips, we measured operation results satisfying its design requirements in 6V supply voltage. After we mount the IR detector chip in the manufactured thermal image system, thermal images were implemented. The obtained thermal images for high and room temperature target objects are sufficiently recognizable. Using the low noise thermal Image system, we expect to obtain thermal images with higher temperature resolution.

• Journal of the Korean Physical Society
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• v.73 no.11
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• pp.1604-1611
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• 2018

Utilizing Sb-based bulk epilayers on large-scale low-cost substrates such as GaAs for fabricating infrared (IR) photodetectors is presently attracting significant attention worldwide. For this study, three sample series of $GaAs_xSb_{1-x}$, $In_{1-x}Ga_xSb$, and $InAs_xSb_{1-x}$ with different compositions were grown on semi-insulating GaAs substrates by using molecular beam epitaxy (MBE) and appropriate InAs quantum dots (QDs) as a defect-reduction buffer layer. Photoluminescence (PL) signals from these samples were observed over a wide IR wavelength range from $2{\mu}m$ to $12{\mu}m$ in agreement with the expected bandgap, including bowing effects. In particular, interband PL signals from $InAs_xSb_{1-x}$ and $In_{1-x}Ga_xSb$ samples even at room temperature show promising potential for IR photodetector applications.

• Korean Journal of Optics and Photonics
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• v.15 no.5
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• pp.423-428
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• 2004

The development of a compact and high performance MWIR thermal imaging sensor based on the SOFRADIR 320${\times}$240 element IRCCD detector is described. The sensor has 20 magnification zoom optics with the maximum 40$^{\circ}$${\times}$30$^{\circ}$ of super wide field of view and 7.6 cycles/mrad of resolving power with the operation of attached micro-scanning system. In order to correct nonuniformities of detector arrays, we have proposed a multi-point correction method using defocusing of the optics and we have acquired the highest quality images. The MRTD of our system shows good results below 0.05K at spatial frequency 1 cycles/mrad at narrow field of view. Experimental data and obtained performances are presented and discussed.

• Korean Journal of Optics and Photonics
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• v.27 no.1
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• pp.18-24
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• 2016

To effectively utilize a flash and predict its effects on an infrared device, it is essential to know the infrared characteristics of the flash source. In this paper, a study of the IR characteristics of flash light sources is carried out. The IR characteristics of three flash sources, of which two are combustive and the other is explosive, are measured with an IR characteristic measurement system over the middle- and long-wavelength infrared ranges. From the measurements, the radiances over the two IR ranges and the radiative temperatures of the flashes are extracted. The IR radiance of flash A is found to be the strongest among the three, followed by those of sources C and B. It is also shown that the IR radiance of flash A is about 10 times stronger than that of flash B, even though these two sources are the same type of flash with the same powder. This means that the IR radiance intensity of a combustive flash source depends only on the amount of powder, not on the characteristics of the powder. From the measured radiance over MWIR and LWIR ranges for each flashes, the radiative temperatures of the flashes are extracted by fitting the measured data to blackbody radiance. The best-fit radiative temperatures (equivalent to black-body temperatures) of the three flash sources A, B, and C are 3300, 1120, and 1640 K respectively. From the radiance measurements and radiative temperatures of the three flash sources, it is shown that a combustive source radiates more IR energy than an explosive one; this mean, in turn, that the effects of a combustive flash on an IR device are more profound than those of an explosive flash source. The measured IR radiances and radiative temperatures of the flash sources in this study can be used to estimate the effects of flashes on various IR devices, and play a critical role for the modeling and simulation of the effects of a flash source on various IR devices.