• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.2
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• pp.409-415
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• 2012

Recently in industry communication, the efforts that use robot and automation system increased by cooperation with optical communication and industrial Ethernet. In this paper, in order to solve the problem that total network blocking when network fault happens and wiring problem of optical cable, which were big serious disadvantage in industrial optical network systems, we propose bi-directional optical EtherCAT communication technique based on single optical core, which applying WDM method. We describe the content for implementation of WDM bi-directional optical EtherCAT communication module and performance evaluation to verify the performance of related technology as a whole.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.2
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• pp.263-268
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• 2001

This paper analyzes error probability performance adopted the Ray Tracing method efficiently analyzing millimeter wave or optic wave in Inter Vehicle Communication(IVC). Analysis environment analyzed bit error characteristic in 60㎓ band with very powerful to multipath wave, to be large to oxygen absorption and to be good to frequency reuse efficiency. We analyzed bit error characteristic of DS/CDMA system by multi access user in Two-Ray rician channel adopted reflect wave of grand, reflect wave of concrete wall and reflect wave of driving vehicle at side road. Improvement performance is adopted MRC diversity.

• Current Optics and Photonics
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• v.7 no.1
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• pp.28-32
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• 2023

Frequency characteristics of gain-saturated erbium-doped fiber amplifier (EDFA) are experimentally evaluated to mitigate the optical signal fluctuation induced by atmospheric turbulence in terrestrial freespace optical communication systems. Here, an acousto-optic modulator (AOM) is used to emulate optical signal fluctuations induced by atmospheric turbulence. The waveform which is generated in proportion to the refractive-index structural parameters is used to drive the AOM at various periodic frequencies. Thus, the dependence of the signal fluctuation suppression on the frequency is evaluated. The experiment is conducted using a periodic frequency sweep of the AOM driving voltage waveform and signal input power variation of the amplifier. It is observed that a low periodic frequency and high input signal power effectively suppress the optical signal fluctuation. This study evaluates the experimental results from the high-pass filter and gain-saturation characteristics of the EDFA.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.5
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• pp.428-434
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• 2010

In this paper, we propose intelligent SAN(Ship Area Network) which is reliable transmission by integration of optical network of wire communication and Zigbee of wireless communication. We also implement module for remote control and constitute, managing for a various sensors and a controllers which are connected SAN integration network It will be help to prevent accident of ship to monitor work environment, real time monitoring of a equipment and main compartment of a poor ship inside. And it will be also available to enhance labor reduction, sailing safety and sailing economical efficiency of ship inside.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.3-6
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• 2005

In this thesis, We researched on the characteristics of optical tunable filter that selects the channel by the wavelength changes of transmission spectrum when we apply outer physical quantities on a fiber bragg grating by using Fabry-Perot Interformer's operational principle.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1157-1158
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• 2008

This paper describes the interface designs of Optical-Camera Electronic unit with a DFPA(Detector Focal Plane Assembly) and IDHU(Image Data Handling Unit) which meet the top-level requirement of a satellite system. Especially, the designs on the image format and timing of the Header information for the correct reconstruction of the image in the Groundstation are explained in detail.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.208-209
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• 2004

We propose a dynamic controlling system of dispersion compensation by uisng electromagnetically inudced grating. This has potential applications for active control of dispersion compensation in a broad specteal range of WDM fiber-optic communication channels.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.3
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• pp.238-242
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• 1988

It is analyzed how performance of phase-locked loop driven by photodetector current in optical receiver will be changed under the condition that Gaussian thermal noise, pattern noise and shot noise are present and the loop has the nonzero detuning frequency. The phase error variance cahnges with the circuit configuration and the produced noise models. The analyzed results are applied to the previously implemented 90.194Mbps optic system whose loop filter is the improved active noninverting 1-st order lag-lead type.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1983.10a
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• pp.44-47
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• 1983

Through intensity modulation induced by micro bending of an optical fiber, a sensor detects the pressure and frequency of acoustic wave has been implemented. Axial slots on the cylinder suface with a period of 5.5 mm induce efficient microbending of the fiber, and a rubber sleeve covering the fiber enhances the fiber. Compared with a conventional hydrophone, it has a low minimum detectable pressure and can detect acoustic wave in 100Hz - 2KHz range.

• Journal of Electrical Engineering and information Science
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• v.2 no.3
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• pp.95-98
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• 1997

A nonlinear optical-microwave interaction is carried out in an uniplanar CPW-to-Slotline ring resonator on the semi-insulating GaAs substrate, in which a Schottky photodetector is monolithically integrated as a coupling gap. When the capacitive reactance of the detetor is modulated, the parametric amplification effect of the mixer occurs. In this device structure, the parametric amplification gain of 20 dB without the applied bias in RF signal is obtained. This microwave optoelectronic mixer can be used in the fiber-optic communication link.