• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.7
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• pp.79-87
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• 1997

Untill now, the most well-known cofiguration for waveguide grating router(WGR) is composed of radiative star couplers and arrayed waveguide grating(AWG), which usually suffer form the rdiation loss of around 3dB or more. Therefore, te improved design of WGRs is needed to reduce the loss. In ths paper, we propose a novel WGR composed of multimode interference couplers which have good unifiormity, fabrication tolerance, and very low excess loss, and suggest the efficient algorithm to find the proper path length differences of AWG for given channel spacing and channel assignment to each output prot. The simulated spectral responses of the proposed WGR using the finite difference beam propagation method (BPM) show that the excess loss is less than 0.3dB and the crosstalk less than -25dB in case of 4x4 WGR, and the excess loss less than 0.4dB and the crosstalk less than -25dB in case of 8x8 WGR for all the channel wavelengths.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.49 no.5
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• pp.22-29
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• 2012

By using the cyclic properties of symmetric balance incomplete block design(BIBD) codes and arrayed-waveguide grating(AWG) routers, a compact optical CDMA network coder-decoder(codec) can be constructed. It can be observed that the various code families obtained by BIBD improve the BER performance compared to M-sequence code.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5A
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• pp.359-369
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• 2005

For large capacity optical CDMA networks, we propose a shared-type encoder/decoders based on an tunable wavelength converter(TWC) and an arrayed waveguide grating (AWG) router. 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.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2431-2433
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• 1999

Phase errors of arrayed waveguide degrade the performance of AWG router, especially for dense WDM system. So it is necessary to measure the phase error and to compensate. The analysis method of the interference signal from the low coherence interferometer to measure the path length difference phase error is studied. The interference signal generated assuming the intentional path length difference errors of 0.1$\sim$0.4${\mu}m$ are analyzed and the results show that the path length difference phase error of ${\Delta}L$ within ${\pm}14^{\circ}$ of sampling phase error can be accurately measured.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2013-2014
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• 2006

For large capacity optical CDMA networks, we propose a shared-type encoder/decoder based on an tunable wavelength conveter (TWC) and an arrayed waveguide grating (AWG) router. Feasibility of the structure of the proposed encoder/decoder for dynamic code allocation is tested through simulations using three types of wavelength/time 2-D codes, which are the generalized multi-wavelength prime code(GMWPC), the generalized multi-wavelength Reed-Solomon code(GMWRSC) and the matrix code. 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.