• Title, Summary, Keyword: Optical mixing

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Aero-optical transmitting effect in the compressible mixing layer

  • Ma, Handong;Gan, Caijun;Li, Lang
    • International Journal of Aerospace System Engineering
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    • v.2 no.2
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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.

Optical Design of Light Guide Plate Material for Slim Liquid Crystal Display (박형 디스플레이를 위한 도광판의 광학설계)

  • Gong, Taewon;Choi, Gyu Jin;Kwon, Jin Hyuk;Park, In Shik;Lee, Sunmook;Woo, DongJin;Gwag, Jin Seog
    • Journal of the Korean institute of surface engineering
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    • v.47 no.5
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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.

Measurement of Zero Dispersion Wavelength in an Optical Fiber Using the Oscillatory Behavior of Four-Wave Mixing Efficiency

  • Kim, Dong-Hwan;Kim, Sang-Hyuck;Jo, Jae-Cheol;Choi, Sang-Sam
    • Journal of the Optical Society of Korea
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    • v.5 no.1
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    • pp.20-24
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    • 2001
  • Non-destructive measurement of zero-dispersion wavelength variation in a dispersion shifted fiber by four-wave mixing technique is carried out. The oscillatory behavior of the four-wave mixing efficiency is utilized for the measurement of the linear dispersion slope and zero-dispersion wavelength. A simple formula useful for engineering estimation of the characteristics of fiber four-wave mixing efficiency is presented.

Frquency Characteristics of Electronic Mixing Optical Detection using APD for Radio over Fiber Network (무선 광파이버 네트웍(RoF)을 위한 APD 광전 믹싱검파의 주파수 특성)

  • Choi, Young-Kyu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.7
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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.

Modeling of Mixed Phosphors in White Light Emitting Diode (백색 발광다이오드에서의 혼합 형광체 모델링)

  • Kim, Dowoo;Gong, Dayeong;Gong, Myeongkook
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.7
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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.

A Study on the One-way Optical Image Transmission Through Optical Fiber by Degenerate Four Wave Mixing (축퇴 4 광파 혼합에 의한 광섬유에서의 광영상 직접전송에 관한 연구)

  • 안병구;이우상;김은수;양인응
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.4
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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.

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Analysis of wavelength conversion by highly nondegenerate four-wave mixing in a semiconductor optical amplifier (반도체 광증폭기내의 Highly Nondegenerate Four-Wave Mixing에 의한 파장변환의 해석)

  • 우상규;이연호
    • Korean Journal of Optics and Photonics
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    • v.10 no.4
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    • pp.294-300
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    • 1999
  • The density matrix is solved more rigorously, compared with the third-order pertubation method used in the conventional theory, for a semiconductor laser amplifier. Then the coupled wave equations are derived to explain the wavelength conversion due to the spectral hole burning in the semiconductor optical amplifier. It is shown that our results can explain the effect of saturation of the population density on the electric polarization, which affects the four-wave mixing and wavelength conversion, better than the conventional theroy where the third-order pertubation is used.

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Optoelectronic Mixing Detection for the Extension of Useable Frequency Range in the Radio over Fiber Network (무선광네트웍(RoF)의 가용 주파수 대역 확장을 위한 광전믹싱 광검파)

  • Choi, Young-Kyu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.10
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    • pp.2189-2196
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    • 2009
  • Theoretical analysis is presented for expending of the usable frequency range of optoelectronic mixing detection in the radio over fiber network system. We define the normalized gain to evaluate the performance of the optical mixing detection, and conform the possibilities of detection for the high frequency signals beyond the cutoff frequency of a photodiode. Optical mixing detection mechanism is analyzed by solving the continuity equation for the carriers of a photodiode. The normalized gain is independent on the signal frequency and the frequency difference between the optical signal and the local signal. Also, the amplitude of the local signal and the bias voltage are needed to be optimized at the same time in order to maximize the normalized gain.