• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3B
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• pp.91-99
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• 2008

In this paper, we design the function of ULSLE(Upper Layer Shared LAN Emulation) to provide both the efficient LAN service and compatibility with 802.1D bridge in Hybrid two-stage AWG based WDM-PON. The ULSLE layer lies above MAC control layer in order to provide a mean to interface WDM-PON and 802.1D bridge. It also performs LAN emulation based on PON-Tag which is only used to decide both the transmission mode and the destination of frames transmitted from ONUs. That is, the PON-Tag is not used for downstream frames but destination address field in original frame instead. This decreases the processing overhead and complexity caused by PON-Tag at OLT and ONU. The verification of designed ULSLE is performed according to the specific scenarios based on transmission mode and destination using OPNET.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3A
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• pp.153-159
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• 2005

In this paper, we propose All-Optical WDM Buffer System for resolving the contention of Packets in Optical Packet Switching System. The proposed system consists of tunable wavelength converters based on SOA, N×N AWG, and fiber delay lines. This structure can reduce ASE and cross-talk noise because the contending packets are sent and buffered through each different path determined by a wavelength routing. We also performed buffering experiment for two contending WDM optical pulses with each 50ns width, and found that the contending problem is resolved well.

• Journal of the Optical Society of Korea
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• v.10 no.4
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• pp.169-173
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• 2006

This paper describes an efficient optimal design method for an arrayed waveguide grating (AWG) having MMI coupler with flattened transfer function. The objective function is the norm of the difference between calculated and target spectra. To analyze the AWG transfer function, the Fresnel-Kirchhof diffraction formula was employed and the design variable was optical path difference of each array waveguide. The (1+1) Evolution Strategy was applied to an eight-channel coarse wavelength division multiplexing (CWDM) AWG as the optimization tool. For obtaining a broadened spectrum, we use a MMI coupler and the variation in optical path difference at each array waveguide changes the shape of the transfer function to obtain the optimal spectrum shape.

• Journal of the Optical Society of Korea
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• v.10 no.1
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• pp.33-36
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• 2006

This paper describes an efficient optimal design method for an arrayed waveguide grating (AWG) with flattened transfer function. The objective function is the norm of the difference between calculated and target spectra. To analyze the AWG transfer function, the Fresnel-Kirchhof diffraction formula was employed and the design variable was optical path difference of each array waveguide. The (1+1) Evolution Strategy was applied to an eight-channel coarse wavelength division multiplexing (CWDM) AWG as the optimization tool. The optimized transfer function will considerably improve the system performance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.5
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• pp.1035-1040
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• 2009

We propose a new encoder/decoders based on an tune able wavelength converter(TWC) and an arrayed waveguide grating(AWG) router for large capacity optical CDMA networks. The proposed encoder/decoder treats codewords of wavelength/time 2-D code simultaneously using the dynamic code allocation property of the TWC and the cyclic property of the AWG router, and multiple subscribers can share the encoder/decoder in networks. Feasibility of the structure of the proposed encoder/decoder for dynamic code allocation is tested through simulations using two wavelength/time 2-D codes, which are the generalized multi-wavelength prime code(GMWPC) and the generalized multi-wavelength Reed-Solomon code(GMWRSC). Test results show that the proposed encoder/decoder can increase the channel efficiency not only by increasing the number of simultaneous users without any multiple-access interference but by using a relatively short length CDMA codes.

• Korean Journal of Optics and Photonics
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• v.18 no.3
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• pp.185-189
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• 2007

A novel technology for CWDM (Coarse Wavelength Division Multiplexer) utilizing a PLC (Planar Lightwave Circuit)-AWG (Arrayed Waveguide Grating) fabrication process is proposed. BPM (Beam Propagation Method) Simulation results on the employed parabolic-horn-type input slab waveguide of AWG and the performance of the 20 nm-channel spacing CWDM with flattened passband are presented. Waveguides of $0.75{\triangle}%$ have been used in this experiment and the insertion loss at the peak wavelength is 3.5 dB for a Gaussian spectrum and is 4.8 dB for a flat-top spectrum. The bandwidth at 3 dB is better than 10 nm and 13 nm for Gaussian and flat-top spectra, respectively.

• Journal of the Optical Society of Korea
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• v.8 no.3
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• pp.99-103
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• 2004

This paper describes the optimal design of an AWG spectrum to meet various specifications and improve some physical parameters. The objective function is the norm of the difference between design parameters and target values. To obtain the design parameters, the Fourier model is employed and the design variables arc spacing of array waveguide, width of array waveguide, optical path difference, and focal length. The (1+1) Evolution Strategy is employed as the optimization tool. The optimization procedure is applied to a 16-channel AWG and the optimized design variables will considerably improve the system performance.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.172-173
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• 2001

다중 광접속 방법 중 CDMA는 많은 수의 주소(개별 사용자를 위한 채널)를 제공하고 광 패킷 전송 방법에 있어서는 패킷들의 충돌을 피하기 위한 복잡한 장치를 필요로 하지 않는다는 장점을 가지고 있다. LED와 같은 Incoherent 광원을 이용하는 광 CDMA를 위한 여러 가지 광 코드와 암호화 방식이 제안되어 왔으며, 파장/시간 이차원 광 코드를 이용하는 방식은 AWG mux/demux 또는 AWG 라우터를 이용하여 광 코드가 용이하게 구현될 수 있음이 보고된 바 있다. (중략)

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.287-287
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• 2004

• TTA Journal
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• s.146
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• pp.94-96
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• 2013