• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1369-1375
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• 2007

The recent, a large capacity of telecommunication networks is required in order to it is in proportion to capacity of information communication increase and to satisfy a demand because of the demand about Internet, a multimedia service of internet, Video of internet protocol(VoIP), Audio/Video streaming. As a result, DWDM(Dense Wavelength Division Multiplexing)technologies are emerging to be a prevailing the method of solving it without additional optical fiber network building and high-speed equipment. Therefore this thesis proposed the optical filter of fiber/multilayer slab coupled structure combining it to multilayer slab waveguide by polishing the cladding of one side of fiber to design the optical filter having these functions. When a separation distance of fiber and slab was $3{\mu}m$, The optical filter proposed as the simulation result was satisfied with a DWDM filter characteristic with FWHM of 0.1nm on TM mode and TE mode as 32nm polarization independence in a communication window of $1.3{\mu}m$ when center wavelength was each ${\lambda}_0=1.274755{\mu}m$ and ${\lambda}_0=1.30591{\mu}m$.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.106-107
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• 2001

표면 플라즈몬 공명(SPR：Surface Plasmon Resonance) 현상은 금속이나 유전체 박막의 두께 및 광학계수 등의 측정이나 센서로 주로 응용되어 왔다. 특히, 최근에는 SPR을 이용한 광 센서나 광 변조기, 파장필터, 광 스위치 등의 광소자에 대한 연구가 많이 되고 있다 본 논문에서는 액체의 농도에 따라 유전 상수가 변하는 것을 이용하여 SPR 광센서가 가능함을 보였다. (중략)

• Korean Journal of Optics and Photonics
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• v.11 no.3
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• pp.193-197
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• 2000

A polarized mode convertible, wavelength tunable optical filters with acoustic barriers and acousto-optic effect have been produced in LiNb03 substrate utilizing the Ti double diffusion technique. Polarization conversion in excess of 81 % and a spectral width of -200 kHz (-1.83 nm) were achieved at a wavelength of 1551.6 nm and RF frequencies of 173.07 kHz and 173.05 kHz for both transverse electric (TE) and transverse magnetic (lM) input polarizations, respectively. The electrical driving power was 10.97 mW and reduced to about 10% of one for an optical filter without an acoustic barrier. A linear tuning rate of 8.2 nmlMHz and sidelobe intensity of -4 dB was demonstrated. rated.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.58.1-58.1
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• 2015

단주기 변광성들의 적외선 광도곡선이 가시광선 광도 곡선과 어떠한 차이가 있는지 알아보기 위해 주기가 하루 이내로 짧은 다양한 유형의 변광성을 대상으로 보현산 천문대의 1.8m 반사망원경과 적외선검출기(KASINICS)를 이용한 J($1.25{\mu}m$), H($1.64{\mu}m$), K($2.15{\mu}m$)필터 관측을 수행하였다. 관측 대상은 맥동변광성으로 분류되는 BO Lyn외 2개 대상, 격변변광성으로 분류되는 RX And외 3개 대상, 그리고 식변광성으로 분류되는 V1007 Cas외 1개 대상이다. IRAF를 이용한 전처리 및 구경 측광을 실시하여 각 필터별 적외선 광도곡선을 얻었다. 이를 통해 현재 각 분류 대상별 주기분석과 여러 해 동안 관측한 자료를 이용하여 각 대상들의 장주기에서의 변광 요인 유무도 확인하여 가시광선 광도곡선과의 비교 분석 연구를 수행하고 있다. 격변변광성의 경우 가시광 광도 곡선이 주로 강착원반의 더 뜨거운 내부고리와 대기에 의한 것인 반면 적외선 광도 곡선은 동반성과 차가운 강착원반에 의한 것이라 여겨지며, 맥동변광성과 식변광성의 경우도 가시광선과 적외선이 서로 다른 깊이를 보게 될 것이므로 파장대별 최대 밝기 위치와 광도 윤곽에서의 차이가 기대된다.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.3
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• pp.349-356
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• 2015

Remote monitoring partial discharge sensor, equipping with hybrid filter combining optical and electrical noise reduction capabilities and with signal integrating function to calculate total arc energy, was investigated. Hybrid filter showed insensitivity to fluorescent and incandescent lamps under simulated distribution panel condition. Signal integrating function showed selective detection capability corresponding to different arc energy levels, while convention arc sensor had difficulty to discriminate arc energy level due to bursty arc waveform and peak level detection characteristics. The sensor showed possibility for application to remote monitoring partial discharge sensor, since it detected arc energy level corresponding to normal open and close discharge in low voltage 100A MCCB at 2m distance.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.1
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• pp.23-28
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• 2003

We report a switchable RGB color filters for Lab on a chip. Ink color filter devices are fabricated by PDMS patterning process. The optical transmission in the ultra-violet and visible wavelengths of color filters have been investigated. The ink color filters are characterised by the slope and shape of the spectrum. The transmission of red/yellow filter consists of curves with a sharp cut-off spectrum at 600 and 500 nm. The blue output of the ink filter has 80% peak transmission and weak red-leak, while the green ink filter has 48% peak transmission and red-leak.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.7
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• pp.42-49
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• 1999

In this paper, we proposed a simple measurement method to find the behaviors of the fiber-to-waveguide coupler. The polished fiber blocks and planar waveguides on silicon dioxide were fabricated independently and then optically coupled by physical pressure. Several kinds of polymer with different refractive indices were used for waveguide films. The proposed method makes it possible to measure the center wavelength, bandwidth, extinction ratio, and polarization dependence of the coupler during fabrication procedure. The wavelength sensitivity increased with refractive index of polymer. The symmetric planar waveguide structure and isotropic property of guiding materials reduced polarization dependent property. Insertion loss of the coupler was less than 0.5dB. It is expected that our measurement method is useful for developing various optical devices using evanescent coupling between polished fiber and planar waveguide such as optical modulators and filters etc.

• Journal of the Korea Society of Computer and Information
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• v.19 no.2
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• pp.101-107
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• 2014

This study is proposed the novel PPG sensor device and the signal processing method to replace the acceleration sensor that is used to reject motion artifacts contained in photoplethysmography(PPG). The proposed method is to reject motion artifacts by an adaptive filter based on the estimated motion artifact by using a blue LED light. To evaluate the performance of the proposed method experimentally, We did design a novel sensor consisted of blue/red LEDs and photo-sensor and implemented, and then rejected the motion artifacts by using an adaptive filter and the implemented sensor. In the results of the experiments, it is shown that the proposed sensor device and signal processing can reconstruct the PPG signal despite the occurrence of motion artifacts, and also that the SNR was 4.5 times of moving average filter. According to the experimental results, the proposed method can be applied to design a low-cost device.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1191-1194
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• 2003

At present, the fabrication of optical filter for optical communication mostly depends on handwork, and only a few companies are propelling semi-automatic systems compounded with automatic and hand-operated methods. The measurement evaluation of optical filters is not commonly useful, so it causes difficulties in the producing field. And the packaging process becomes a very unstable process because the filters are judged from the results that they are not measured and immediately packaged during that process. In this situation, the automatic assembly system of optical filter for communication is extremely important and has begun to make its appearance as the most necessary technology for developing optical communication component with high-functionality. In this paper, we constructed systems of assembly and performance evaluation for micro optical collimator. And by using that, we designed a system capable of performance evaluation and assembly of film filter of about 30 $\mu\textrm{m}$ thickness as well as optical filter for common communication.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.2 s.179
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• pp.57-64
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• 2006

Optical filters in WDM are passive communication components used in case of transmitting and reflecting lights with specific wavelengths. In this paper, a novel mechanism for the automatic and optical alignment has been presented. It includes minimum axes not to be coupled each other. The automatic spectrum inspection system has been developed to improve the alignment time of reference optical ray, spectrum inspection time and inspection quality, simultaneously. It has been confirmed that the proposed spectrum inspection system is faster, more precise and more reliable than those based on the conventional handwork.