• Title/Summary/Keyword: Optical

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Optical Signals Using Superposition of Optical Receiver Modes

  • Lee, Jae Seung
    • Current Optics and Photonics
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    • v.1 no.4
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    • pp.308-314
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    • 2017
  • A particular optical receiver has its own optical receiver modes (ORMs) determined by its optical and electrical filters. Superposing the ORM waveforms at the transmitter, we can generate a new type of optical signals, called ORM signals. After optical detection, they produce pre-specified voltage waveforms accurately, which is advantageous for digital signal processing. Assuming a Gaussian optical receiver, where the optical and electrical filters are Gaussian, we illustrate various phase-shift keying ORM signals using two ORMs by changing their relative phase. We also illustrate multi-level ORM signal patterns using two or more ORMs.

Optical Path Analysis and Experiments for Optical Microphone (광 마이크로폰 개발을 위한 광 경로해석 및 실험)

  • Kwon, Hyu-Sang;Kim, Kyong-Woo;Kim, Jin-Ki;Che, Woo-Seong
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.3
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    • pp.210-217
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    • 2007
  • The theoretical formulations are derived for calculating optical power change for intensity modulated fiber optical microphone. The optical power change is due to optical paths, misalignment and geometry of optical coupler. Based on the theoretical equations, three different optical couplers are simulated with respect to several angles of optical couplers. In order to evaluate the formulation, a multi-mode to multi-mode coupler which is one of abovementioned optical couplers is designed and characterized by carving out both static experiments and dynamic experiments. Considering experimental results, this paper conclude that the theoretical formulations is very useful for design optical coupler and this kind of fiber optic sensor is adequate to microphone.

Optics in China: past, present and future

  • Gan, Fuxi
    • Proceedings of the Optical Society of Korea Conference
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    • 2000.02a
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    • pp.68-68
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    • 2000
  • In this paper a very brief review of historical development of optical science and technology in China is presented. More attention has been pain on Modem Optics, which developed since 1950s. The recent development of optical science and technology in following fields are introduced. 1. Optical engineering and instrumentation (tracking theodolites, high speed cameras, satellite laser ranging systems, satellite flying attitude control, cameras for remote sensing, astronomical optical instrument) 2. Applied optics (adaptive optics, optical metrology, infrared optics, optical processing, optical holography) 3. Laser science and technology (ultrashort pulse lasers, UV-X ray lasers, high power laser facilities and laser fusion, laser isotope separation) 4. Laser and nonlinear materials (rare earth elements doped laser glasses and crystals, tunable laser crystals, borate series and organic nonlinear crystals) 5. Optoelectronic science and technology (Optical communication, optical data storage, optical computing) The current situation and developing prospect of optical and optoelectronic industry in China are presented. Furthermore it points out that the optical industry could be developed vigorously only if products development capacity is enhanced and new products industrialization is heightened. The main research and education institutions in the optics field in China, as well as the Chinese Optical Society (COS) are introduced.

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Design and Fabrication of Microlens Illuminated Aperture Array for Optical ROM Card System (Optical Card 시스템에서의 마이크로렌즈 조사 광프로브 어레이 설계 및 제작)

  • Kang, Shin-Ill;Kim, Seok-Min;Kim, Hong-Min;Lee, Jee-Seung;Lim, Ji-Seok;Busch, Christopher
    • Transactions of the Society of Information Storage Systems
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    • v.2 no.1
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    • pp.1-6
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    • 2006
  • An optical ROM card system which using an optical probe array generated by Talbot effect was proposed as new robust storage solution. To improve the optical density and to decrease the power consumption of the system, it is very important to make the spot sizes of optical probes smaller as well as to increase the optical efficiency from the light source to optical probes. In this study, a microlens illuminated aperture array for generating high efficiency optical probe away with small beam spot was designed and fabricated using monolithic lithography integration method. The maximum intensity of optical probes of microlens illuminated aperture array increased about 12 times of that of aperture array, and the full width half maximum of the optical probe at Talbot plane generated by microlens illuminated aperture array was $0.77{\mu}m$.

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Performance Evaluation of Bidirectional Optical Amplifiers for Amplified Passive Optical Network Based on Broadband Light Source Seeded Optical Sources

  • Kang, Byoung-Wook;Kim, Chul-Han
    • Journal of the Optical Society of Korea
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    • v.15 no.1
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    • pp.4-8
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    • 2011
  • We have evaluated the performances of bidirectional optical amplifiers which were suited for the cost-effective implementation of amplified bidirectional passive optical networks (PONs). First, we measured the maximum gains of two simple bidirectional optical amplifiers implemented without using any optical components for the suppression of reflected signals. From the results, the maximum gains of two simple bidirectional amplifiers with a broadband light source (BLS) seeded optical source were limited to be 27 dB due to the reflection-induced in-band crosstalk, when the reflectance coefficients were measured to be -33 dB in both directions. Then, we have also implemented a bidirectional optical amplifier with two band splitters for the amplified bidirectional PON where the two different wavelength bands were allocated to the downstream and upstream signals transmission. In our measurement, we confirmed that the maximum gain of bidirectional optical amplifier with two band splitters could be increased to more than 30 dB owing to the efficient suppression of in-band crosstalk.

All Optical Logic Gate Based On Optical Bistability of DFB SOA (DFB SOA의 광쌍안정 특성을 이용한 전광논리구현)

  • Kim, Byung-Chae;Kim, Young-Il;Lee, Seok;Woo, Deok-Ha;Yoon, Tae-Hoon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.04b
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    • pp.112-113
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    • 2002
  • Optical bistability can be applied to the optical logic. optical signal processing and optical memory. We have measured the optical bistability of DFB-SOA and demonstrated all-optical OR logic gate using switching characteristics of DFB-SOA.

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Design and Implementation of a optical buffer using optical wavelength converters (파장 변환기를 이용한 광버퍼의 설계 및 구현)

  • 황현용;곽동용
    • Proceedings of the IEEK Conference
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    • 2003.11c
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    • pp.109-112
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    • 2003
  • Wavelength division multiplexing technology is a promising solution for the next generation optical networks. Optical buffer is a key component for optical packet switching system. It can be used to hold optical packets and to resolve the contention of optical packets. In this paper, we implemented a optical buffer using optical wavelength converters and demonstrated that optical packets are delayed successfully.

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Design of Slim Optical Pickup for Blu-ray Disk (광 정보 저장 기기용 초소형 광픽업 설계)

  • 이상혁;정미숙;손진승;송태선;박노철;박영필
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.386-389
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    • 2003
  • Recent issues in Optical Disk Drive (ODD) are focused on small size. Blu-ray Disk (BD), using blue laser (405nm wavelength) and high NA (0.85) objective lens. can store 25Gbyte on a conventional 12cm optical disk. Small Form Factor Optical (SFFO) drive uses 3cm disk which can store 1.5Gbyte on a disk. This kind of Small Form Factot Optical (SFFO) drive correspond to PCMCIA type memory (Compact Flash or Micro Drive). Preferably, Optical Disk has relatively low cost of the storage media per Byte rather than PCMCIA type memory. To make Small Form Factor Optical (SFFO) drive. optical pickup and its component must be miniaturized. Miniaturization of the component needs new concept of Optical Pickup. This paper is focused on two main subjects. One is Objective Lens design which can be manufactured on a wafer, and the other is optical path design of the pickup which has 2mm thickness.

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Optical Axis Auto-adjustment of Objective Lens in Optical Disc Drives (광디스크 드라이브에서의 대물렌즈 자동광축보정)

  • Ryoo, Jung-Rae;Moon, Jung-Ho;Cho, Ju-Pil
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.6
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    • pp.558-563
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    • 2008
  • Optical axis misalignment, which represents the position deviation of the objective lens from the optical axis, is an inevitable assembly error in an optical pick-up. Since the laser power intensity varies with respect to the distance from the optical axis, the misalignment leads to variation of the laser spot power intensity, which is one of the critical factors increasing data bit-error-rate in optical disc drives. In this paper, an auto-adjustment scheme for optical axis alignment is proposed to eliminate the undesirable variation of the laser spot power intensity in optical disc drives. An envelope of the data RF signal is extracted and utilized to detect the optical axis misalignment. Then an adjustment input is added to the driving input of the tracking actuator to shift the objective lens to the optical axis. Finally, the feasibility is verified by experiments.

All-optical Integrated Parity Generator and Checker Using an SOA-based Optical Tree Architecture

  • Nair, Nivedita;Kaur, Sanmukh;Goyal, Rakesh
    • Current Optics and Photonics
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    • v.2 no.5
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    • pp.400-406
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    • 2018
  • The Semiconductor Optical Amplifier (SOA)-based Mach-Zehnder interferometer is a major contributor in all-optical digital processing and optical computation. Optical tree architecture provides one of the new, alternative schemes for integrated all-optical arithmetic and logical operations. In this paper, we propose an all-optical 3-bit integrated parity generator and checker using SOA-MZI-based optical tree architecture. The proposed scheme, able to process input signals at a desired operating wavelength, has been characterized using RZ-modulated signals at 10 Gbps. The maximum extinction ratios achieved at the output of the parity generator and checker are 10 dB and 8 dB respectively.