• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
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• pp.21-21
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• 1997

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1197-1199
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• 2001

TFM(Transeverse Flux Motor) is switched reluctance motor with new structure of novel design concept based on the high efficiency and power density compare to induction motor used on wide industrial field. This paper realized FWM asymmetric converter drive control system for TFM using IGBT and DSP.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.12
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• pp.2963-2967
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• 2015

The pump-probe scheme is used to analyze the cross-phase modulation penalty of a single-mode fiber in a WDM system. The pump signal is assumed to be a periodically modulated input like a raised sinusoidal. The periodic signal models an alternating bit sequence, and leads to an analytical expression of CPM penalty which is measured by EOP. The derived expression shows good agreement with numerical results in conventional single-mode fiber systems over a wide range of channel spacing, ${\Delta}f$. In dispersion-shifted fiber systems when ${\Delta}f$ < 100GHz, the derived expression shows increased discrepancy with the numerical results due to the increased FWM. This is not a surprising because the pump-probe scheme is used to analyze system performance degradation due to CPM.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.487-489
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• 2004

As the electrodes are not needed, the electrodeless lamps using the induction discharge have a long lifetime and are robust against the variable output condition of a ballast. This paper proposed a dimmable resonant inverter for the electrodeless lamps. The proposed resonant inverter formed a half bridge inverter adopted FWM to control the average output power of the inverter and the illumination of a lamp. In this paper, the proposed dimming algorithm was described and the prototype experimental setup for 100W electrodeless lamps was carried out to verify the validity of the proposed dimming method.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.8
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• pp.69-75
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• 1998

We demonstrate wavelength conversion of 2.5Gb/s optical signals by four-wave mixing (FWM) in a semiconductor optical amplifier (SOA). We investigate the effect of input pump and signal powers on the coversion efficiency, optical signal-to-noise ratio (OSNR) and extinction ratio to be a measure of performance in a wavelength converter. As a result, we show that the maximum bit error rate (BER) performance can be obtained by co promising among high-vonversion efficiency (minimum Pprobe), high-OSNR (maximum Pprobe) and low-cross-gain saturation effects (Pprobe kept at least 6dB weaker than Ppump). In our experiment, we obtain optimum performance at +3 dBm pump power and -6dBm signal power. The power penalty incurred in the wavelength conversion can be minimized by careful selection of the input pump and signal powers. We show that about 0.5dB power penalty for 3.2nm wavelength coversion at 10-10 BER is achievable.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.13-16
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• 2012

We demonstrate an optical gate architecture using a single SOA to perform AND, OR and NOT logic functions. Simple reconfigurable all-optical logic operations are implemented using RZ modulated signals at 40 Gb/s. Contrast ratio and extinction ratio values have been analysed for the different types of logic gates. Maximum extinction ratio and contrast ratio achieved are 19dB and 17.2 dB respectively. Simple structure and potential for integration makes this architecture an interesting approach in photonic computing and optical signal processing.

• Journal of the Optical Society of Korea
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• v.18 no.6
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• pp.639-645
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• 2014

In this paper, the scheme of a single module for simultaneous operation of all-optical computing circuits, namely half adder and half subtractor, are realized using semiconductor optical amplifier (SOA) based logic gates. Optical XOR gate by employing a SOA based Mach-Zehnder interferometer (MZI) configuration is used to get the sum and difference outputs. A carry signal is generated using a SOA-four wave mixing (FWM) based AND gate, whereas, the borrow is generated by employing the SOA-cross gain modulation (XGM) effect. The obtained results confirm the feasibility of our configuration by proving the good level of quality factor i.e. ~5.5, 9.95 and 12.51 for sum/difference, carry and borrow, respectively at 0 dBm of input power.

• Korean Journal of Optics and Photonics
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• v.11 no.5
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• pp.330-334
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• 2000

A new pha~e lock loop (PLL) IS proposed and demonstrated fat clock recovery from 40 Gblt/s time-dIvision-multiplexed (TDM) optical pulse tri.lin, The proposed clock lecovery scheme lmproves the Jitter effecl cOlmng from the clock. pulse laser of harmonically-mode locked flber laser The cross-corrdation frequency component between the optical Signa] and an optical clock pulse tram is deteCled as a fonr-wave-mixing (FWM) SIgnal generated in SOA. The lock-in freqnency range of the clod. recovery IS found to be within 10 KHz. 0 KHz.

• Proceedings of the Optical Society of Korea Conference
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• 2003.07a
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• pp.16-17
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• 2003

지난 수년간 인터넷 보급에 따른 급격한 통신량 증가에 따른 요구는 차세대 통신 기술인 WDM을 구축하게 되었고 이에 따라 WDM 라우팅 기술과 스위칭 기술이 절실히 필요로 하게 되었다. WDM에 있어서 다른 경로나 목적지로 신호를 보내기 위해서는 신호의 파장이 변환 되어야 하므로 신호의 파장변환은 라우팅에 있어 핵심적인 기술 중 하나로 인식되어지고 있다 현재 사용되어지고 있는 전광 파장 변환기는 주로 SOA (Semiconductor Optical Amplifier)의 비선형 특성인 XGM, XPM, FWM등을 이용한 것으로서 편광 민감성, ASE에 의한 SNR 감소, 신호크기 변형과 높은 가격으로 인해 안정적인 파장변환기로 쓰기에는 다소 무리가 있다. (중략)

• Electronics and Telecommunications Trends
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• v.34 no.5
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• pp.91-98
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• 2019

Optical frequency comb generators have been investigated as a signal source capable of generating highly stabilized ultrafast pulse lasers. The precise control of the optical frequency comb spacing by RF clock signals has led to a revolutionary paradigm shift in the precise measurement of time and frequency. Optical frequency combs also have advantages such as stable frequency spacing, stable number of lines, and robustness. Owing to these characteristics, optical frequency combs have been applied to the fields of high precision optical clock, communication, spectroscopy, waveform generation, and astronomy. In this article, we introduce the properties (i.e., generation methods, advantages, and so on) of various optical frequency combs, and discuss the expected future technological trends and applications.