• Title/Summary/Keyword: Mach-Zehnder

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Fabrication of Mach-Zehnder Interferometric Modulator Using Proton-Diffused Channel Waveguide (양자확산 LiNbO$_3$ 광도파로를 이용한 Mach-Zehnder 간섭계 구조의 광변조기 제작)

  • 김종성
    • Proceedings of the Optical Society of Korea Conference
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    • pp.264-268
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    • 1990
  • A guided-wave electro-optic Mach-Zehnder interferometric modulator was fabricated on X-cut LiNbO3 . The channel waveguides were formed by proton diffusion with self-aligned SiO2-cladding. A mach-Zehnder interferometric modulator with arm lengths of 7mm has been fabricated and tested at 0.6328${\mu}{\textrm}{m}$. Its modulation depth with V$\pi$ of only 3.5V was 85% and the 3dB bandwidth was 1.6KHz. For high speed operation, the electrode dimension should be reduced to have smaller R, L, and C.

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Mechanically induced Mach-Zehnder interferometers based on long-period fiber grating pair (기계적으로 구현된 장주기 광섬유 격자 Mach-Zehnder 간섭계)

  • 장현수;조준용;이경식
    • Korean Journal of Optics and Photonics
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    • v.14 no.4
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    • pp.365-368
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    • 2003
  • We have demonstrated mechanically induced Mach-Zehnder interferometers (MZI) based on a long-period fiber grating pair. The transmission spectra, the interference fringes, and the fringe spacing of the long-period fiber grating pairs have also been investigated experimently and analytically. The fringe spacings of the fabricated LPG pairs agree well with the theoretical results.

All-optical mach-zehnder interferometric wavelength converter monolithically integrated with loss-coupled DFB probe source (Loss-Coupled DEB LD집적 Mach-Zehnder 간섭계형 파장 변환기)

  • 김현수;김종회;심은덕;백용순;김강호;권오기;오광룡
    • Korean Journal of Optics and Photonics
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    • v.14 no.4
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    • pp.454-459
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    • 2003
  • We report the first demonstration of 10 Gb/s wavelength conversion in a Mach-Zehnder interferometric wavelength converter monolithically integrated with a loss-coupled DFB probe source. The integrated device is fabricated using a BRS (buried ridge stripe) structure with an undoped InP clad layer on the top of a passive waveguide to reduce high propagation loss. The device exhibited a static extinction ratio of 11 dB. Good performance at 10 Gb/s is obtained with an extinction ratio of 7 dB and a power penalty of 2.8 dB at a 10$^{-9}$ bit error rate.

The Measurements of Vibration Displacement of the Piezoelectric Exciter Using Mach-Zehnder Optical Fiber Interferometer (Mach-Zehnder 광섬유 간섭계를 이용한 압전형 진동발생기의 동특성 조사)

  • Cho, Seung-Il;Kim, Sung-Boo;Lee, Jong-Kyu;Lee, Yong-Bong;Lee, Doo-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.10
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    • pp.1044-1049
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    • 2006
  • The vibration exciter with the accurate calibration requires a low distortion along a single axis over a wide range of frequency. The fabricated piezoelectric exciter was composed of a base, piezoelectric element(Venitron PZT 5A), electrode and seismic mass. Its performance characteristics is evaluated the Mach-Zehnder optical fiber interferometer. The phase of the optical wave passing through the optical fiber around the piezoelectric element was related the vibrational amplitude with a change of the applied sinusoidal voltage on the piezoelectric element. The dynamic characteristics of vibration exciter can be obtained by measuring the vibrational amplitude with a sinusoidal applied voltage on the piezoelectric element. The sensitivity of the fabricated piezoelectric exciter had a 0.4 nm/V which was uniform up to 20 kHz.

Loop-back System Using Mach-Zehnder Modulator (Mach-Zehnder 변조기를 이용한 Loop-back System)

  • Kim, Hui-Ju;Gang, Dong-Seong;Jeon, Geum-Su;Ban, Jae-Gyeong
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.38 no.7
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    • pp.479-485
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    • 2001
  • In this paper, we propose optical subcarrier mutiplexing(SCM) transceiver module for base station(BS) that has no optical source and can be used for full-duplex communication over single optical fiber. In this method we retransmit optical modulated signal to the central office(CO) using loop-back system with a ring type Mach-Zehnder modulator(MZM) in BS, where optical source is transmitted from the CO. We have modeled the ring type MZM and were conformed that the measured results were in good agreement with the modeling. In the ring type MZM, the optical symmetric position of the MZM is very important in RF signal transmission.

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Detecting Characteristics of Ultrasonics Generated by Partial Discharge in Insulating Oil Using the Optical Fiber Mach-Zehnder Interferometer (광섬유 Mach-Zehnder 간섭계를 이용한 부분방전 초음파 검출특성)

  • 이상훈;심승환;이광식;김달우
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.4
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    • pp.50-56
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    • 2003
  • It is well known that a partial-discharge(PD) in insulation oil is the source of various physical and chemical phenomena, such as heat, light, gas, chemical transformation, electric current, electromagnetic radiation and ultrasonics. The PD can be detected by measuring one of these changes. Although some techniques are employed in this purpose, several obstacles interfere with an on-line measurement. Ultrasonic-wave detection is a useful method for the diagnosis of the transformer-insulation condition. Conventionally, ulyrasonic waves are detected by Piezo-electric transducer, but we use optical method that has many advantages. In this paper, we constructed a Mach-Zehnder interferometer with optical fiber and investigated the principle of operation. Test arrangement is based on the needle-plane electrode system in oil and applied AC high voltage. Ultrasonic waves were detected and analyzed with wavelet transform.

Single Photon Interference Experiments in a Sagnac-type Mach-Zehnder Interferometer (Sagnac 형태로 변형된 Mach-Zehnder 간섭계를 이용한 단일광자 간섭실험)

  • Um, Jayoon;Kim, Yong Soo;Kim, Heonoh
    • Korean Journal of Optics and Photonics
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    • v.23 no.2
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    • pp.71-76
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    • 2012
  • A Sagnac-type Mach-Zehnder interferometer(SMZI) is a very stable instrument with respect to phase drift because all optical paths can share common optical components. We have observed very stable interference fringes in single photon interference experiments with an extremely attenuated laser beam, and with heralded single photons prepared from polarization correlated photon pairs in type-II spontaneous parametric down-conversion. The phase stability is measured to be about ${\pm}0.18$ rad for the SMZI, in contrast, conventional MZI showed the phase fluctuation of around ${\pm}1.02$ rad.

광통신용 $Ti:LiNbO_3$외부 광변조기/스위치 설계

  • 김창민;정석원
    • 전기의세계
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    • v.44 no.9
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    • pp.28-37
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    • 1995
  • 외부 광스위치/변조기로는 차단형(cut-off type)[1], 균일 방향성 결합기(uniform directional coupler)[2-4], Mach-Zehnder 간섭계(Mach-Zehnder interferometer)[5-7], 교번 .DELTA..betha. 방향성 결합기(alternation directional coupler)[8-9], 교차 결합기(crossed coupler[10-11], Y-분기 방향성 결합기(Y-branch directional coupler)[12-14] 등의 여러가지가 연구되어졌다. 본 논문에서는 위에서 열거한 여러 가지 광변조기를 해석, 설계하는데 기본이 되는 광결합 이론으로 normal mode 이론과 coupled mode 이론을 소개한다. 아울러 이러한 이론들을 이용하여 전술한 변조기 중 균일 방향성 결합기, Y-분기 방향성 결합기, Mach-Zehnder 간섭계의 광스위칭/변조 원리를 살펴본다.

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