• Title/Summary/Keyword: optical sciences

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Assessment and Correction of the Spectral Quality for the Savart Polarization Interference Imaging Spectrometer

  • Zhongyi Han;Peng Gao;Jingjing Ai;Gongju Liu;Hanlin Xiao
    • Current Optics and Photonics
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    • v.7 no.5
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    • pp.518-528
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    • 2023
  • As an effective means of remotely detecting the spectral information of the object, the spectral calibration for the Savart polarization interference imaging spectrometer (SPIIS) is a basis and prerequisite of information quantification, and its experimental calibration scheme is firstly proposed in this paper. In order to evaluate the accuracy of the spectral information acquisition, the linear interpolation, cubic spline interpolation, and piecewise cubic interpolation algorithms are adopted, and the precision of the quadratic polynomial fitting is the highest, whose fitting error is better than 5.8642 nm in the wavelength range of [500 nm, 820 nm]. Besides, the inversed value of the spectral resolution for the monochromatic light is greater than the theoretical value, and the deviation between them becomes larger with the wavelength increasing, which is mainly caused by the structural design of the SPIIS, together with the rationality of the spectral restoration algorithm and the selection of the maximum optical path difference (OPD). This work demonstrates that the SPIIS has achieved high performance assuring the feasibility of its practical use in various fields.

Design and Performance Analysis of BLSR/4 WDM/SHR in All-Optical Transport Network (완전 광전달망에서 BLSR/4 WMD/SHR의 설계 및 성능 분석)

  • 강안구;최한규;김지홍;김광현;김호건;조규섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.10B
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    • pp.1832-1840
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    • 1999
  • This paper proposed a network to implement all optical bidirectional BLSR/4 WDM/SHR allowing restoration in the event of a failure. The proposed network can provide a high degree of transparency using all-optical components with no electric implementation and effective failure restoration due to BLSR/4 WDM/SHR architecture. This paper also presented a genetic simulation model for the survivability analysis of the proposed BLSR/4 WDM/SHR under failure scenarios, the restoration performance of the proposed network is analyzed in terms of performance parameters such as propagation time, processing time, optical switch time.

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Thermo-optic Effects of Bragg Grating Optical Temperature Sensor

  • Ahn, Kook-Chan;Lee, Sang-Mae;Lee, Gwang-Seok;Park, Seung-Bum
    • International Journal of Aeronautical and Space Sciences
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    • v.3 no.2
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    • pp.24-30
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    • 2002
  • This paper demonstrates a comparison of linear and nonlinear analyses for thermo-optic effects of optical temperature sensor based on the etched silica-based planar waveguide Bragg grating. Topics include theoretical analyses and experiment of the etched planar waveguide Bragg grating optical temperature sensor. Theoretical models with nonlinear than linear temperature effect for the grating response based on waveguide and plate deformation theories agree with experiments to within acceptable tolerance.

Magnetic and Magneto-Optical Properties of Conjugated Polymers: A New Frontier

  • Gangopandhyay, Palash;Foerier, Stijn;Vangheluwe, M.;Koeckelberghs, Guy;Verbiest, Thiery;Persoons, Andr
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.23-24
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    • 2006
  • Magnetic and magneto-optical properties of regioregular (>99%) poly(3-dodecylthiopenes are investigated. Faraday rotation of spin-coated films show extremely large Verdet constants, falling strongly with decreasing regioregularity. EPR spectroscopy at room temperature shows the presence of about 1 spin/190 monomers, indicative of delocalisation beyond a single polymer chain. SQUID measurements on the polymer give an effective magnetic moment of about 48900 mB, corrsponding to a S-value of 25.000. The Weiss-constant is 1.33 K indicating ferromagnetic coupling. Our experimental results show that organic polymer magnets can be prepared. Large MO effects allow the use of these materials in all-organic MO-sensors and devices.

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A Study on the Birefringence Properties of Single Mode Optical Fiber (단일모우드 광섬유의 Birefringence특성에 관한 연구)

  • 김은수;박한규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.7 no.4
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    • pp.161-166
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    • 1982
  • In this paper, the intrinsic birefringence and twist-induced rotation of the single mode optical fiber have been investigated. On the analysis, the optical fiber has been modeled as a linear retarder and the intrinsic linear retardation of the single mode optical fiber is approximately found to be 2.57'/m from the measurement. Theoretically analyzing the twist-induce rotation by the purturbation theory, it is found that the magnitude of the twist-induced rotation varies linearly with the twisted angle. And this theorerical result has been in good accord with the experimental result.

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A Study on the Optical Character Recognition using Optical Correlators Computer (광상관기를 이용한 컴퓨터용 광문자인식에 관한 연구)

  • 박현철;송우영;박한규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.9 no.4
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    • pp.179-183
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    • 1984
  • Only K=$log_2$N reference patterns called principal components are sufficient to identify one out of N characters, calculated by computer and fablicated. An incogerent optical correlator is used for correlation coefficient measurements and it is shown that that this method has better discrimination ability that analog measuments using matched filter.

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Comparative Efficacy of Four Imaging Instruments for Breast Cancer Screening

  • Mehnati, Parinaz;Tirtash, Maede Jafari
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.15
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    • pp.6177-6186
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    • 2015
  • Sensitivity and specificity are the two most important indicators in selection of medical imaging devices for cancer screening. Breast images taken by conventional or digital mammography, ultrasound, MRI and optical mammography were collected from 2,143,852 patients. They were then studied and compared for sensitivity and specificity results. Optical mammography had the highest sensitivity (p<0.001 and p<0.006) except with MRI. Digital mammography had the highest specificity for breast cancer imaging. A comparison of specificity between digital mammography and optical mammography was significant (p<0.021). If two or more breast diagnostic imaging tests are requested the overall sensitivity and specificity will increase. In this literature review study patients at high-risk of breast cancer were studied beside normal or sensitive women. The image modality performance of each breast test was compared for each.

All-Optical WDM Buffer System realized by NOLM and Feedback Loop (NOLM과 피드백 루프에 의해 구현된전광 WDM 버퍼 시스템)

  • 이승우;윤경모;이용기;엄진섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.5A
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    • pp.514-520
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    • 2004
  • In WDM networt a WDM buffer is one of essential elements for realizing all-optical packet switching system. In this paper, we propose and demonstrate a single loop type all-optical WDM buffer system. The proposed one consists of NOLM and feedback loop, and provides more than 40 turns buffering (more than 20${\mu}\textrm{s}$) for single input pulse (1550nm, width: 20㎱) before selected by control signal pulse (1553nm, width: 30㎱).

The Diagnosis and Treatment of Primary Chorioretinitis using Optical Coherence Tomography in a Dog (Optical Coherence Tomography를 이용한 원발성 맥락망막염 이환견의 진단 및 치료)

  • Ji, Dongbeom;Yoo, Suk-Jong;Seo, Kangmoon;Jeong, Manbok
    • Journal of Veterinary Clinics
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    • v.30 no.4
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    • pp.324-328
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    • 2013
  • A 5-year-old intact male Yorkshire terrier dog was referred with a 1-week history of blindness. In both eyes, menace responses and pupillary light reflexes were absent. The indirect ophthalmoloscopy revealed multiple small gray-white and discoloration lesion in mid-nontapetum area in both eyes. Electroretinograms showed diminished amplitude of a- and b-waves. Multifocal serous retinal detachments were detected with optical coherence tomography (OCT) over the small gray-white and discoloration lesion in the fundus. After one week of treatments, the indirect ophthalmoloscopy showed that irregular patches and hyperpigmentation in the center of hyperreflectivity area. Reattachment and retinal thinning were observed by the OCT. The results indicate that OCT scanning is considered to be a useful method for retinal evaluation in dogs with chorioretinitis.