• International Journal of Aerospace System Engineering
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• 제2권2호
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• pp.79-82
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• 2015

The handicap for investigating the aero-optical effect focuses on the accurate prediction on the index refraction fluctuation or density fluctuation. In recent years, with the development of CFD techniques and optical experimental techniques, the comprehension have developed on the aero-optical transmitting effect in many kinds of complex flow. This study mainly introduces the optical aberration in compressible mixing layer. And then the debates about the mechanism of aero-optical effects and assessment of image blur also present.

• 한국표면공학회지
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• 제47권5호
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• pp.233-238
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• 2014

In this paper, in order to achieve slim and light liquid crystal display, we examine the optical conditions that can obtain uniform light with higher optical efficiency over whole light guide plate (LGP) through simulation. Furthermore, to overcome the issues of hot spot in front of red, green, and blue light emitting diodes (RGB LEDs) source and non-uniform color mixing, we propose four shaped color mixing bars tied up with the LGP and check the optical characteristics of the LGP with them by simulation. Consequently, we could know the optical conditions of improving optical efficiency and optical uniformity in the LGP through the optical design. Also we confirmed that the issues of the hot spot and non-uniform color mixing in edge type LED could be solved by using the ${\bigwedge}$-shaped window color mixing bar.

• 전기학회논문지
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• 제58권7호
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• pp.1386-1392
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• 2009

An analysis is presented for super-high-speed optical demodulation by an avalanche photodiode(APD) with electric mixing. A normalized gain is defined to evaluate the performance of the optical mixing detection. Unlike previous work, we include the effect of the nonlinear variation of the APD capacitance with bias voltage as well as the effect of parasitic and amplifier input capacitance. As a results, the normalized gain is dependent on the signal frequency and the frequency difference between the signal and the local oscillator frequency. However, the current through the equivalent resistance of the APD is almost independent of signal frequency. The mixing output is mainly attributed to the nonlinearity of the multiplication factor. We show also that there is an optimal local oscillator voltage at which the normalized gain is maximized for a given avalanche photodiode.

• 한국전기전자재료학회논문지
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• 제26권7호
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• pp.567-574
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• 2013

An optical model is proposed in the white LED using phosphor and LED chip. In this paper a new model that describes the absorption rate and quantum efficiency with increasing the mixing ratio of phosphor in silicone, and the allotment of the phosphor absorption optical power in the several phosphor mixing in the silicone. Single phosphor in silicone from the optical measurement data before and after molding, the solution to get the blue optical power and the phosphor emission optical power is proposed. By these solution the absorption rate and the quantum efficiency was obtained. The model with single phosphor mixing in the silicone the validity was confirmed.

• 대한전자공학회논문지
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• 제25권4호
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• pp.460-466
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• 1988

In this paper, the theory and experiments on the one-way optical image transmission through optical fiber by using degenerate four wave mixing in BSO single crystal are demonstrated. From the theoretical analysis, the diffraction efficiency of phase conjugate wave in BSO single crystal is greatly dependent on applied electric field intensity, diffraction grating period formed in the crystal and incident beam ratio, those are also in good agreement with the experimental results. Based on the experimental results, we have arranged the typical degenerate four wave mixing system in the optimal conditions (applied electric field, E. = 5kV/cm` diffraction grating period, 3\ulcorner` beam ratio of backward pump wave versus signal wave, 2.7) and realized one-way optical image transmission system through optical fiber using BSO single crystal.

• 한국광학회지
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• 제10권4호
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• pp.294-300
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• 1999

본 논문에서는 반도체 광증폭기내에서 four-wave mixing을 발생시키는 spectral hole burning을 더욱 정확하게 해석하기 위하여 밀도행렬을 기존의 방법에 비하여 정확하게 푸는 방법에 대하여 설명하고 이러한 밀도행렬에 대한 수치해석을 실시하여 그 해를 구한다. 이렇게 구한 결과를 통해 반도체 광증폭기내에서의 four-wave mixing에 의한 파장변환을 설명하는 결합 파동 방정식을 유도하고 이것의 해를 구하여 반도체 광증촉기에서의 파장변환이 어떻게 발생하는 지를 설명하고 3차 섭동을 이용하여 계산된 기존의 결과와 비교한다.

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.323-324
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• 2007

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.325-326
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• 2007

• 한국광학회:학술대회논문집
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• 한국광학회 2006년도 동계학술발표회 논문집
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• pp.245-246
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• 2006

• 한국정보통신학회논문지
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• 제13권10호
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• pp.2189-2196
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• 2009

광파이버 네트웍에서 광전믹싱 광검파의 가용 주파수대역 확장을 위한 이론을 제시하고 시뮬레이션을 실시하였다. 광전믹싱 광검파의 정규화 이득을 정의하고, 검파소자의 차단주파수를 초월하는 고주파 영역의 신호도 검파가 가능함을 확인하였다. 포토다이오드 내부의 캐리어 천이에 대한 연속방정식을 풀어서 광전믹싱 현상의 메카니즘을 해석하였다. 정규화 이득은 신호주파수와 차주파수의 크기에 의존하였으나, 포토다이오드에 흐르는 광전류의 크기는 신호주파수와는 무관하였다. 신호 검파효율의 최대화를 위해서는 바이어스 전압과 국부신호의 진폭을 동시에 최적화할 필요가 있다.