• Title/Summary/Keyword: Optical mixing

Search Result 347, Processing Time 0.041 seconds

Approach of Self-mixing Interferometry Based on Particle Swarm Optimization for Absolute Distance Estimation

  • Li, Li;Li, Xingfei;Kou, Ke;Wu, Tengfei
    • Journal of the Optical Society of Korea
    • /
    • v.19 no.1
    • /
    • pp.95-101
    • /
    • 2015
  • To accurately extract absolute distance information from a self-mixing interferometry (SMI) signal, in this paper we propose an approach based on a particle swarm optimization (PSO) algorithm instead of frequency estimation for absolute distance. The algorithm is utilized to search for the global minimum of the fitness function that is established from the self-mixing signal to find out the actual distance. A resolution superior to $25{\mu}m$ in the range from 3 to 20 cm is obtained by experimental measurement, and the results demonstrate the superiority of the proposed approach in comparison with interpolated FFT. The influence of different external feedback strength parameters and different inertia weights in the algorithm is discussed as well.

Optical nonlinearity in genetic material (유전물질의 비선형 광학 특성)

  • Park, Byeongho;Jun, Seong Chan
    • Transactions of the Society of Information Storage Systems
    • /
    • v.10 no.1
    • /
    • pp.19-22
    • /
    • 2014
  • Optical nonlinear property is utilized to the wave generation, generating the beam at intended wavelength, and optical computing systems. The genetic material, which is the DNA with helical structure in nano-scale, is fascinating for optics communities due to artificially controllable sequence that determines the physical and chemical property. Nonlinearity of DNA was investigated by the four wave mixing experiment, which is with two incident beams located at 1550nm and 1650nm. The four output beams including incident beams are emitted from genetic material such as 1461nm and 1763nm by nonlinear characteristic. The 1461nm beam which is generated by four wave mixing phenomena was observed by optical spectrum analyzer.

Nonresonant-Pump Four Wave Mixing : New Scheme of Phase Matching for Third Order Nonlinear Laser Spectroscopy (비공명펌프 사광자혼합 : 3차 비선형 레이저 분광법을 위한 새로운 위상정합법)

  • 이은성;최대식;이재용;한재원
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2002.07a
    • /
    • pp.222-223
    • /
    • 2002
  • 3차 비선형 광학현상을 이용한 레이저 분광학은 코헤런트 반스톡스 라만산란(Coherent Anti-Stokes Raman Scattering, CARS)이나 축퇴 사광자혼합(Degenerate Four-Wave Mixing, DFWM)이 기계공학의 연소진단이나 화학분야에 응용된 이래 활발히 연구되어져왔다.[1] 비선형 광학현상의 특성상, 발생한 신호는 입사 레이저광들과의 위상정합조건이 만족되는 특정한 방향으로만 진행하고 레이저광처럼 가간섭성을 갖는다. (중략)

  • PDF

Optical Decryption System of Binary Image Using Two-Wave Mixing in Photorefractive Crystal (광굴절 매질에서 2광파 혼합을 이용한 이진 영상 복호화 시스템)

  • 최상규;신창목;서동환;김철수;김수중
    • Proceedings of the IEEK Conference
    • /
    • 2002.06b
    • /
    • pp.83-86
    • /
    • 2002
  • We suggest binary image decryption system using two-wavc mixing in Photorefractive crystal. Compared with a conventional method, this method can make optical alignment easily, and brighten the encrypted image even if a small input signal, by index grating of photorefractive crystal. Also it can reconstruct the encrypted image by only reference beam in real time.

  • PDF

Input Signal Power Range Extension by Optimal Control of CW Power in Four-Wave-Mixing Wavelength Converter (4파 혼합 파장 변환기에서 CW 파워 조절을 통한 입력 신호 영역 확장)

  • 장원봉;박경현;박효훈
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2003.02a
    • /
    • pp.158-159
    • /
    • 2003
  • In four-wave-mixing wavelength converter, we investigated the performance through simulation by using VPI tool, changing the input signal power and CW power at 2.SGb/s. Controlling optimal CW power to each input signal power, we extended the input signal power range to 20dB, which guarantees the minimum power penalty.

  • PDF

Fabrication and electro optical properties of stressed liquid crystal cell

  • Lee, Jung-Min;Park, Jin-Seol;Kang, Dae-Seung
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.681-682
    • /
    • 2009
  • We fabricated a stressed liquid crystal cell by mixing liquid crystal with a photo-polymer. By carefully choosing the mixing ratio between liquid crystal and the polymer, and by suitable mechanical shearing of the substrates, we demonstrated feasible electro optical properties for displays.

  • PDF

Optical Decryption System of Binary Image Using Two-Wave Mixing in Photorefractive Crystal (광굴절 매질에서 2광파 혼합을 이용한 이진 영상 복호화 시스템)

  • 최상규;신창목;서동환;김철수;김수중
    • Proceedings of the IEEK Conference
    • /
    • 2002.06a
    • /
    • pp.207-210
    • /
    • 2002
  • We suggest binary image decryption system using two-wave mixing in photorefractive crystal. Compared with a conventional method, this method can make optical alignment easily, and brighten the encrypted image even if a small input signal, by index grating of photorefractive crystal. Also it can reconstruct the encrypted image by only reference beam in real time.

  • PDF

Optical Arithmetic Technique Using Optical Phase Conjugate Wave (위상 공액파를 이용한 광학적 연산 방식)

  • 엄순영
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 1990.02a
    • /
    • pp.95-101
    • /
    • 1990
  • Parallel optical arithmetic techniques have been developed using the correlation property of optical phase conjugate wave generated by degenerated four wave-mixing. In this paper, conventional rectangular-type coded pattern used for optical logic system is replaced by circular one for effective beam coupling in a photorefractive $BaTiO_3$ material. By adequately adjusting the distance between circular-type pixels of the input pattern and grouping the correlated output, optical binary half addition/subtraction, binary multiplication and, matrix-matrix computation are demonstrated.

  • PDF

The study on the mixing character of synthetic molding sand by power change (혼사전력 변화에 의한 합성사의 혼련특성에 관한 연구)

  • Kim, Young-Sik;Jeong, Jeong-Yeon;Lee, Jong-Nam
    • Journal of Korea Foundry Society
    • /
    • v.4 no.1
    • /
    • pp.12-20
    • /
    • 1984
  • In order to investigate the effect of size of sand grains, bentonite content and moisture on mixing power, standard mixing power, permeability, green compressive strength and green mold hardness were measured with mixing time, and also coated layer of mixed sand with time was observed by optical microscope and scanning electron microscope. From this experiment, the results were summarized as follows. 1. Mixing power increased as size of sand grains decreased. 2. Mixing power increased gradually as bentonite content increased and in particular, increased rapidly in 7-10% bentonite. 3. Mixing power increased as moisture content decreased. 4. The mixing time required to get the optimum mixing power decreased as moisture content and grain size increased, but increased as bentonite content increased.

  • PDF