• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.2
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• pp.59-65
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• 2011

All-optical signal processing is expected to offer advantages in speed and power consumption against over electronics signal processing. It has a potential to solve the bottleneck issues of ultra-high speed communication network nodes. All-optical serial-to-parallel and parallel-to-serial data converters would make it possible to easily process the serial data information of a high-speed optical packet without optical-to-electronic-to-optical data conversion. In this paper, we explain the principle of simple and easily expandable all-optical serial-to-parallel and parallel-to-serial data converters based on Mach-Zehnder interferometers. We experimentally demonstrate these data converters at 10Gbit/s serial data rate. They are useful all-optical devices for the all-optical implementations of label decoding, self-routing, control of variable packets, bit-wise logical operation, and data format conversion.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.10
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• pp.79-88
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• 2003

We demonstrate a novel all-optical packet switching system that is suitable for optical ring networks. For the demonstration, video signals are encoded into optical packets which are composed of header and payload. The optical packets are all-optically processed at a switching node based on all-optical header processor, packet-level clock extraction, bit-level clock extraction, all-optical data format converter and so on.

• Korean Journal of Optics and Photonics
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• v.13 no.5
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• pp.421-424
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• 2002

By using SOA (Semiconductor Optical Amplifier) based devices, an all-optical half adder has been successfully demonstrated at 10 Gb/s. All-optical XOR and AND gates are utilized to realize SUM and CARRY. Since SUM and CARRY have been simultaneously realized to form the all-optical half adder, complex calculation and signal processing can be achieved.

• 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.

• Journal of the Optical Society of Korea
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• v.6 no.4
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• pp.165-171
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• 2002

By using a semiconductor optical amplifier and a cross-phase modulation wavelength converter, fundamental all-optical logic gates including NOT, AND, NOR, XOR, and XNOR have been newly proposed and implemented. Realization of these all-optical logic gates will bring up not only all-optical networks but also all-optical computing and signal processing.

• Journal of the Optical Society of Korea
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• v.20 no.4
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• pp.464-469
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• 2016

All-optical non-return-to-zero (NRZ) -to- return-to-zero (RZ) data-format conversion has been successfully demonstrated using a semiconductor optical amplifier in a fiber-loop mirror (so-called SOA-loop mirror) with a continuous-wave (CW) holding beam. The converted RZ signal after pulse compression has been used to create a 40 Gb/s OTDM (Optical Time Division Multiplexing) signal. Here is proposed an NRZ-to-RZ conversion method without any additional optical clocks, unlike conventional methods based on optical AND logic. In addition, it has the merit of operating at various bit-rate speeds without any controlling device. Moreover, it has a simple structure, and it can be used for all-optical bit-rate-flexible clock recovery.

• ETRI Journal
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• v.23 no.3
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• pp.106-110
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• 2001

Subpicosecond all-optical switching method based on the simultaneous two-photon coherence exchange is proposed and numerically demonstrated. The optical switching mechanism is based on the optical field induced dark resonance swapping via nondegenerate four-wave mixing processes. For potential applications of ultrafast all-optical switching in fiber-optic communications, 10-THz channel number independent quantum router is discussed.

• Korean Journal of Optics and Photonics
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• v.13 no.2
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• pp.151-154
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• 2002

All-optical OR logic gate is realized by use of gain saturation and wavelength conversion in the semiconductor optical amplifiers (SOA). It is operated by the nonlinearity of the SOA gain and hence to obtain the sufficient gain saturation of the SOA, pump signals are amplified by an Er-doped fiber amplifier (EDFA) at the input of the SOA. The operation characteristics of all-optical OR logic gate are successfully measured at 2.5 Gbit/s.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.551-558
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• 2016

In multifiber all-optical networks, optical amplifiers are used for amplifying multiple optical signals with different wavelengths in fibers. An optical amplifier operates when any of lightpaths passes through it. Therefore, it should simultaneously amplify as many lightpaths as possible for efficiently utilizing its power. This paper proposes a dynamic lightpath establishment scheme considering the use efficiency of the optical amplifiers and the depletion of the wavelength resources in multifiber all-optical networks. The proposed scheme provides a routing and wavelength assignment strategy that reduces both the power consumption of the optical amplifiers and the blocking probability of the lightpath establishment. Through simulation experiments, we demonstrate the effectiveness of the proposed scheme.

• Journal of the Optical Society of Korea
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• v.14 no.2
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• pp.137-141
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• 2010

We report, for the first time to our knowledge, observation of polarization bistability from 1.55-${\mu}m$ wavelength single-mode VCSELs of a conventional cylinder-shape under control of their driving current, and demonstration of all-optical flip-flop (AOFF) operations based on the bistability with optical set and reset pulse injection at a 50 MHz switching frequency. The injection pulse energy was less than 14 fJ. The average on-off contrast ratio of the flip-flopped signals was about 7 dB. These properties of the VCSELs will be potentially useful for future high-speed all-optical signal processing applications.