• Title/Summary/Keyword: Optical coherence

Search Result 341, Processing Time 0.027 seconds

2-D OCT image implementation using low coherence SLD (Low coherence 특성의 SLD를 이용한 2차원 OCT 영상 구현)

  • 정태호;박양하;오상기;김용평
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2003.02a
    • /
    • pp.290-291
    • /
    • 2003
  • Optical Coherence Tomography is a new medical dianostic imaging technology which can perform micron resolution cross-sectional or tomograpic imaging in biological tissue. In this paper, we analyze OCT system. And we have 2-dimensional OCT image implementation using low coherence SLD.

  • PDF

Measurement of Spatial coherence function and Directional coherence function of Propagating Laser Beam by using Wigner Distribution Function

  • Lee, Chang-Hyuck;Kang, Yoon-Shik;Noh, Jae-Woo
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2009.02a
    • /
    • pp.449-450
    • /
    • 2009
  • The spatial coherence and propagation property of laser beam propagating through several optical components were studied experimentally by using the measurement of Wigner distribution function. It is shown experimentally that the Wigner function measurement yields total degree of coherence, beam quality parameter, and the near and the far field information of the propagating beam. More complete characterization of the laser beam was achieved by applying the Schmidt mode decomposition to the Wigner distribution function, spatial coherence function and directional coherence function. Fine details of coherence property are understood by the characteristics of the contributing eigenmodes.

  • PDF

Measurement of Glucose concentration using Polarization Sensitive Low Coherence Interferometer (Polarization Sensitive Low Coherence Interferometer를 이용한 Glucose 농도 측정)

  • 이상원;김법민
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2003.02a
    • /
    • pp.128-129
    • /
    • 2003
  • 최근 수년간 polarimetry, Raman spectroscopy, near infrared (NIR) absorption spectroscopy, NIR scattering, optoacoustics 등의 방법을 통하여 비침습적으로 Glucose의 농도를 측정하려는 연구가 많이 시도되었다. 일반적으로 이들 방법은 sensitivity 와 signal-to-noise ratio가 매우 낮고 복잡한 알고리즘이 요구되어져 glucose 농도 측정에 한계가 있음이 드러났다. 본 연구에서는 polarization sensitive optical coherence tomography (PS-OCT)에 사용되는 polarization sensitive low coherence inter-ferometer (PS-LCI) 기법을 이용하여 비침습적으로 glucose의 농도 측정을 가능하게 하는 시스템 개발에 중점을 두었다. (중략)

  • PDF

Optical Coherence Tomography Based on a Continuous-wave Supercontinuum Seeded by Erbium-doped Fiber's Amplified Spontaneous Emission

  • Lee, Ju-Han;Jung, Eun-Joo;Kim, Chang-Seok
    • Journal of the Optical Society of Korea
    • /
    • v.14 no.1
    • /
    • pp.49-54
    • /
    • 2010
  • In this study, the use of a continuous-wave (CW) supercontinuum (SC) seeded by an erbium-doped fiber's amplified spontaneous emission (ASE) for optical-coherence tomography imaging is experimentally demonstrated. It was shown, by taking an in-depth image of a human tooth sample, that due to the smooth, flat spectrum and long-term stability of the proposed CW SC, it can be readily applied to the spectral-domain optical-coherence tomography system. The relative-intensity noise level and spectral bandwidth of the CW SC are also experimentally analyzed as a function of the ASE beam power.

Coherence Studies of Photons Emitted from a Single Terrylene Molecule Using Michelson and Young’s Interferometers

  • Yoon, Seung-Jin;Trinh, Cong Tai;Lee, Kwang-Geol
    • Journal of the Optical Society of Korea
    • /
    • v.19 no.6
    • /
    • pp.555-559
    • /
    • 2015
  • Coherence length (time) is a key parameter in many classical and quantum optical applications. Two interferometers – Michelson and Young’s double-slit – are used to characterize the temporal coherence of single photons emitted from single terrylene molecules. For quantitative analysis, a dispersion-related distortion in the interference pattern of a Michelson interferometer is carefully corrected by a simple dispersion compensation. Additionally, it has been demonstrated that Young’s interferometer can be used in temporal coherence studies at the single photon level with high accuracy. The pros and cons of the two systems are discussed. The measured coherence lengths in the two systems are consistent with one another under the self-interference interpretations.

Study on Optical Feedback in Optical Fiber Laser (광섬유 레이저에서의 광궤환에 대한 연구)

  • Choi, Kyoo-Nam
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.11 no.5
    • /
    • pp.985-990
    • /
    • 2007
  • The method of enhancing visibility in optical fiber sensor was investigated by improving coherence length of light source. The optical feedback technique is used to enhance coherence length in fiber laser which generates laser in near infrared wavelength region and utilizes low loss characteristics of optical communication grade fiber. In this paper, the effect to coherence length by short and long optical feedback paths are investigated by using Mach-Zehnder interferometer technique. The effect to coherence length by changing optical feedback power and optical modulation are investigated. The spectral drift was calculated by measuring the degree of phase perturbation in unbalanced Mach-Zehnder interferometer having loom path difference. The short optical feedback path was effective to reduce spectral drift to 450kHz/sec and the long optical feedback path in combination with short optical feedback path was found to further reduce spectral drift to 50kHz/sec.

Optical Coherence Tomography with Sinusoidal-Wave Drive an Optical Delay Line using Piezoelectrics Strecher (정현파로 구동되는 PZT 광경로 지연기를 이용한 광 간섭 단층촬영시스템)

  • Kim, Young-Kwan;Kim, Yong-Pyung
    • Korean Journal of Optics and Photonics
    • /
    • v.18 no.4
    • /
    • pp.274-279
    • /
    • 2007
  • We fabricated and characterized an optical delay line for optical coherence tomography (OCT). The delay line was composed of a cylindrical piezoelectric transduce (PZT) and a single mode optical fiber. The OCT system used a duplex scanning optical delay line which was symmetrically driven in the reference and sample arms. We showed that the sinusoidal-wave was superior to a triangular-wave for driving the optical delay line for scanning depth and repeatability.