• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.273-274
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• 2008

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.67-68
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• 2008

• Proceedings of the Optical Society of Korea Conference
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• 2002.11a
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• pp.96-97
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• 2002

• Korean Journal of Optics and Photonics
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• v.1 no.1
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• pp.16-21
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• 1990

The accurate polarization state of the light inside BSO crystal was calculated with consideration of optical activity. By solving Maxwell's equations, the general form of the polarization matrix for any direction of the electric field was obtained. Examples of output polarization states in BSO crystals were also calculated, and their properties were discussed.

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.2
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• pp.97-103
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• 1999

Zinc sulfide is a ll-VI compound with a large direct band gap in the near-UV region and a promising material for blur-light emitting diode and laser diode. It was identified that the structure had zinc blonde structure through the analysis of X-ray diffraction patterns. It's lattice constant was measured to be $a_o=5.411{\AA}$. The optical absorption, photocurrent, and photoluminescence spectra were measured to investigate the optical properties of zinc sulfide single crystal. The optical energy band gap measured at room temperature was 3.61eV The energy band gap of zinc sulfide annealed in zinc vapor at $800^{\circ}C$ was lower 0.1eV than that of as-grown zinc sulfide through the analysis of the photocurrent spectra. The photoluminescence spectra were measured ranging from 30K to 293K for the two cases of as-grown and annealed zinc sulfide. As-grown ZnS single crystal had peaks at 350nm, 392nm, 465nm, and annealed zinc sulfide had peaks at 349nm.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.13-18
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• 2000

In this paper, we use the C light which is a daylight and consider the incident beam having the Gaussian amplitude. We investigated the illuminance distributions and the variation in chromaticity of optical system having the truncated Gaussian amplitude on the focal plane and along the optical axis using the C light source. We also use the three sensitivity functions of human eye(CIE 1931) for wavelengths which are from 380nm to 780nm. When the truncation grade of incident beam having Gaussian amplitude decreases, the size of central spot on the focal plane and the depth of focus along the optical axis decrease, and the variation in chromaticity on the focal plane and along the axis increases rapidly. As the illuminance on the focal plane decreases the variation in chromaticity of optical system increases rapidly, and as the depth of focus increases the variation in chromaticity of optical system decreases.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.2
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• pp.41-55
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• 1989

Successive iteration of geometrical optics(GO)is suggested to calculate wedge diffraction fields. For a wedge and given source, the GO field may be obtained when the fields by the half spaces are found and the shadow regions are determined. Furthermore, one may caluculate the sources which are equivalent to the discontinuities of the GO field along the shadow boundaries and form a new wedge problem with the equivalent sources instead of the original one. It is shown that the field by the wedge and the equivalent sources equals to the diffraction field which GO requires for the complete solution. Also, it is shown that the field generated by the equivalent sources in the unbounded space, or the incident field in the new wedge problem, equls to the diffraction field approximated by the physical optics. The new wedge problem is solved here by another application of the GO to approximate the diffraction field and the result is compared with that by the physical optics. For a validity of the successive iteration of GO , infinite iteration of GO is performed analytically and the convergence is examined ofr conducting wedges, of which the exact solution is available.

• Journal of Korean Ophthalmic Optics Society
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• v.1 no.2
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• pp.63-69
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• 1996

D.c conductivity and optical transmittance of amorphous ($As_2Se_3$)Ag, (x =0, 2, 5, 10mol%) thin films were measured in order to find effects of Ag additives on electrical and optical properties of the films. The d.c. activation energy and the optical gap decreased with increasing Ag contents the Urbach tail was approximately unchangeable for variation of Ag contents. For Ag contents of 5mol% and less, the rate of decrease of the d.c activation energy was more rapidly than that of the optical gap with increasing Ag contents. For Ag contents more than 5mol%, the rate of decrease of the d.c activation energy and the optical gap were nearly the same each other with decreasing Ag contents. So it was appeared that the Fermi level of the films comes close to the mobility edge for Ag contents of 5mol% and less, and the mobility edge comes close the Fermi level for Ag contents more than 5mol%.

• Korean Journal of Optics and Photonics
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• v.18 no.6
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• pp.401-409
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• 2007

A new sheet of back light unit(BLU) to reduce the number of sheets and enhance the optical performances of direct back light unit(BLU) in a liquid crystal display is proposed and designed. In order to improve the straightness and spatial uniformity of brightness of the BLU, we design the new sheet with linear arrays of complicated bar prism by using the fusion of cylindrical lens and bar prism. Then, we investigate and analyze various optical performances of a BLU including the new sheet through an illumination optical system design program. From these results, we determine the optimum geometrical structure of the sheet. Under the optimum condition, the luminance efficiency and spatial uniformity of luminance of the BLU are 53.5% and 83.5% respectively. And the vertical and horizontal widths of the angular luminance distribution are $90^{\circ}$ and $112.5^{\circ}$ respectively. Finally we have fabricated a new BLU sheet according to this design shape by using an ordinary resins.

• 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.