• ETRI Journal
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• v.9 no.2
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• pp.24-35
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• 1987

A Design and Fabrication of 565 Mbit/s Optical Fiber Transmission Link We calculated the transfer functions of optical channel components and formulated the optimum transfer function of optical receiver for optical transmission to show a design rule of fiber optical link for digital transmission. And we evaluated various causes of sensitivity degradation to determine the receiver specification. Also we fabricated and demonstrated a 565Mbit/s single mode fiber optic link, 27km, to show the practicality of designed fiber optic link. The output power of the transmitter was above -3dBm, and the sensitivity of the optical receiver was -37.8dBm which is the same value we expected. Also the dynamic range was more than 25dB.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.10
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• pp.64-72
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• 1995

In this paper, atmospheric turbulence and absorption under clear weather condition, which affect the optical satellite up-link communication between geo-satellites and earth station, were studied. In case of the up-link communication, the received optical power is weakened by pointing loss caused by beam tilt which is the main effect of turbulent atmosphere. This pointing loss directly has relation to the diameter of optical transmitting antenna. From the inverse proportion of the pointing and spaced loss, it is the regions where the diameter of transmitting antenna increases abruptly and the efficient design of transmitting antenna is impossible. In case of using channel coding, it was shown that the peak value of diameter moved to the lower regions of elevation angle with increasing the coding gain and its width was also decreased. In case of considering both coding gain and transmission rate on the design of transmitting antenna, it was known that more coding gain was necessary as transmission rate was increased.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.63-68
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• 2022

Two wavelength reconfigurable optical nodes are designed. One for 20km or shorter link length, and the other for up to 60km link length. While the first one requires no dispersion compensation, the latter needs dispersion compensation fiber included in the node, which requires additional optical amplifier to compensate the insertion loss of DCF. We calculate all the optical path losses in both cases using the typical value of optical components in the market to see the feasibility of the designed optical node. The minimum received power in the node is calculated to be -21.5dBm without DCF and -12.5dBm with DCF, respectively. These received powers are above the receiver sensitivity both for OC-48 and OC-192 according to the previous work.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2691-2695
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• 2009

Nowadays Fiber optical communication systems have limitless bandwidth and can be used for transmitting various multimedia data with in real time. It is necessary to construct integrated service systems that can be used in our society whole to communicate multimedia data such as text, image, audio and video data in fiber optic communication systems. In this paper, we have designed and constructed the fiber optical link application system for multi-video/audio data transmission using only one core optical cable upgrading previous fiber optical communication systems based on WDM (Wavelength Division Multiplexer). Using the proposed fiber optical link application system enables us to managing fiber optical communication systems with only one core optical cable using WDM (Wavelength Division Multiplexer) and DEWDM/Wavelength splitter.

• Journal of Advanced Navigation Technology
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• v.12 no.3
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• pp.201-207
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• 2008

Design rule of optical transmission link consisted of dispersion management (DM) controlling accumulated dispersion in total fiber length by precompensation and postcompensation, and optical phase conjugator (OPC) positioned at mid-way are proposed. DM schemes investigated in this paper are 2 types depending on the position of precompensation and postcompensation; bi-end type and concentration type. It is confirmed that effective residual dispersion ranges, as a design parameter of optical link, of transmission section from transmitter to OPC and transmission section from OPC to receiver are independence on the positions of dispersion compensating fiber (DCF) accomplishing precompensation and postcompensation, if both DCF position is symmetry with respect to OPC.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.6
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• pp.75-82
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• 1997

Today's wireless communication needs the super-high speed for picture transmission as well as voice. The optical communication with the very wide bandwidth is suitable for this demand. To fulfill the optical wireless communication, however, the atmospheric attenuation in rainy weather condition must be overcome. In the optical satellite up-link communication between geo-satellite and earth station, the factors of attenuation are turbulence, pointing error, scattering, and so on. The most serious factor for these is the scattering by rain. Under the weather conditiion of rain and cloud, in this paper, the atmospheic attenuation which affects the optical satellite up-link communication was considered, and the optimum idameter of the optical satellite transmitting antenna in the earth station versus elevation angles, data rates and rainfall rates was presented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5A
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• pp.316-322
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• 2003

We theoretically analyze the properties of nonlinear distortion due to modulation instability (MI), which is a major factor of performance degradation in optical amplified transmission systems, and propose an optical link structure to compensate MI based on the analysis. The proposed MI compensating link structure is composed of optical phase conjugators (OPCs) and dispersion compensating fibers (DCFs) in order to suppress nonlinear effects in optical transmission links. It has been confirmed through computer simulations that the performance of the proposed compensation scheme is superior to that of conventional compensation schemes for 500 km transmission.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9B
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• pp.1518-1526
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• 2000

This paper proposes an optical transmission link design method based on an optimum compensation scheme using dispersion compensating fiber (DCF), so that high-speed long-distance optical transmission would be possible over the conventional standard single mode fiber (SMF) link. The proposed design method provides the maximized transmission distances according to the signal speeds, where the amplifier spacing and repeater spacing are optimized wit respect to self-phase modulation(SPM) due to fiber nonlinearity and amplified spontaneous emission (ASE) noises caused by optical amplifies. It is also shown that there exists an optimum input signal power range balancing the effects of ASE noise and SPM for the given amplifier spacing and repeater spacing.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.270-273
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• 2000

We have fabricated and analyzed photodiodes for optical link with Si pin structures. As the results of experiment, the web patterned photodiode(type C) with $p^{+}$-guard ring showed low junction capacitance of 6~7 pF at $V_{R}$=-5V and high separation ability for optical signal(dark current : $\leq$ 5 nA, optical signal current : $\geq$ 340 nA) due to the small effective $p^{+}$-n junction area and the expanded electric field region. The fabricated Si pin photodiode can be applicable for detecting an optical signal with the wavelength of about 660~670 nm. It can also be integrated with the twin well CMOS structure to develope an one chip based optical receiver IC. IC.C.

• Journal of information and communication convergence engineering
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• v.21 no.2
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• pp.103-109
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• 2023

We investigated the antipodal-symmetric dispersion maps of a dispersion-managed link with a midway optical phase conjugator to compensate for the distorted 960 Gb/s wavelength division multiplexed (WDM) signal caused by these effects. The proposed antipodal-symmetric dispersion map has various shapes depending on the detailed design scheme. We confirmed that the dispersion-managed link designed with the dispersion map of the antipodal-symmetric structure is more advantageous than the conventional uniform dispersion map for compensating WDM channels. It was also confirmed that among the antipodal-symmetric structures, the dispersion map configured with the S-1-profile, in which S is inverted up and down, was more effective for distortion compensation than the dispersion map configured with the S-profile. In particular, we confirmed that the S-1-profile can broaden the optical pulse width intensively at a short transmission distance, more effectively compensating for the distorted WDM channel. Because this structure makes the intensity of the optical pulse relatively weak, it can decrease the nonlinear Kerr effect.