• Title/Summary/Keyword: optics

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Analysis of Acetone Absorption Spectra Using Off-axis Integrated Cavity Output Spectroscopy for a Real-time Breath Test

  • Lim Lee;Yonghee Kim;Byung Jae Chun;Taek-Soo Kim;Seung-Kyu Park;Kwang-Hoon Ko;Ki-Hee Song;Hyunmin Park
    • Current Optics and Photonics
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    • v.7 no.6
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    • pp.761-765
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    • 2023

  • We analyzed the absorption spectra of acetone in the 3.37 ㎛ mid-infrared range using the off-axis integrated cavity output spectroscopy technique to develop a real-time, in-line breath analysis device. The linear relationship between acetone concentration and absorption increase was confirmed as 0.32%/ppm, indicating that the developed device allows for a quantitative analysis of acetone concentration in exhaled breath. To further confirm the feasibility of using our device for breath analysis, we measured the acetone concentration of human breath samples at the sub-ppm level.

  • https://doi.org/10.3807/COPP.2023.7.6.761 인용 PDF

Thermal Analysis and Design of AlGaInP-based Light Emitting Diode Arrays

  • Ban, Zhang;Liang, Zhongzhu;Liang, Jingqiu;Wang, Weibiao;JinguangLv, JinguangLv;Qin, Yuxin
    • Current Optics and Photonics
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    • v.1 no.2
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    • pp.143-149
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    • 2017

  • LED arrays with pixel numbers of $3{\times}3$, $4{\times}4$, and $5{\times}5$ have been studied in this paper in order to enhance the optical output power and decrease heat dissipation of an AlGaInP-based light emitting diode display device (pixel size of $280{\times}280{\mu}m$) fabricated by micro-opto-electro-mechanical systems. Simulation results showed that the thermal resistances of the $3{\times}3$, $4{\times}4$, $5{\times}5$ arrays were $52^{\circ}C/W$, $69.7^{\circ}C/W$, and $84.3^{\circ}C/W$. The junction temperature was calculated by the peak wavelength shift method, which showed that the maximum value appears at the center pixel due to thermal crosstalk from neighboring pixels. The central temperature would be minimized with $40{\mu}m$ pixel pitch and $150{\mu}m$ substrate thickness as calculated by thermal modeling using finite element analysis. The modeling can be used to optimize parameters of highly integrated AlGaInP-based LED arrays fabricated by micro-opto-electro-mechanical systems technology.

  • https://doi.org/10.3807/COPP.2017.1.2.143 인용 PDF KSCI

Beam Shaping and Speckle Reduction in Laser Projection Display Systems Using a Vibrating Diffractive Optical Element

  • Liang, Chuanyang;Zhang, Wei;Wu, Zhihui;Rui, Dawei;Sui, Yongxin;Yang, Huaijiang
    • Current Optics and Photonics
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    • v.1 no.1
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    • pp.23-28
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    • 2017

  • The laser has been regarded as the potential illumination source for the next generation of projectors. However, currently the major issues in applying the laser as an illumination source for projectors are beam shaping and laser speckle. We present a compact solution for both issues by using a vibrating diffractive optical element (DOE). The DOE is designed and fabricated, and it successfully transforms the circular Gaussian laser beam to a low speckle contrast uniform rectangular pattern. Under a vibration frequency of 150 Hz and amplitude of $200{\mu}m$, the speckle contrast value is reduced from 67.67% to 13.78%, and the ANSI uniformity is improved from 24.36% to 85.54%. The experimental results demonstrate the feasibility and potential of the proposed scheme, and the proposed method is a feasible approach to the miniaturization of laser projection display illumination systems.

  • https://doi.org/10.3807/COPP.2017.1.1.023 인용 PDF KSCI