• 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.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2847-2851
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• 2020

A simple water level measurement method based on wavelength division multiplexing (WDM) is proposed and demonstrated. The measurement principle is based on the change of Fresnel reflection occurring at the end facet of the optical fiber tip (OFT). To increase the spatial resolution of water level sensing, a broadband light source (BLS) and an arrayed waveguide grating (AWG) are employed. The OFTs are multiplexed with the dedicated wavelength channels of AWG. By measuring all of the reflection powers reflected at the OFTs with a proposed on-site reflectometer, the water level can be monitored continuously for a fast emergency response. Moreover, it can be implemented easily with the commercially available optical components and devices with the simple configuration.

• ETRI Journal
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• v.35 no.5
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• pp.786-796
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• 2013

In this paper, we propose a hybrid time-division multiplexing and dense wavelength-division multiplexing scheme to implement a cost-effective and scalable long-reach optical access network (LR-OAN). Our main objectives are to increase fiber plant utilization, handle upstream and downstream flow through the same input/output port, extend the reach, and increase the splitting ratio. To this end, we propose the use of an arrayed waveguide grating (AWG) and an erbium-doped fiber amplifier (EDFA) in one configuration. AWG is employed to achieve the first and second objectives, while EDFA is used to achieve the third and fourth objectives. The performance of the proposed LR-OAN is verified using the Optisystem and Matlab software packages under bit error rate constraints and two different approaches (multifiber and single-fiber). Although the single-fiber approach offers a more cost-effective solution because service is provided to each zone via a common fiber, it imposes additional losses, which leads to a reduction in the length of the feeder fiber from 20 km to 10 km.

• ETRI Journal
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• v.24 no.4
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• pp.259-269
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• 2002

Polymers are emerging as new alternative materials for optical communication devices. We developed two types of polymer-based devices for optical communications. One type is for ultra high-speed signal processing that uses nonlinear optical (NLO) polymers in such devices as electro-optic (EO) Mach-Z${\ddot{e}} $ hnder (MZ) modulators and EO 2${\times}$2 switches. The other is for WDM optical communications that use low-loss optical polymers in such devices as 1${\times}$2, 2${\times}$2, 4-arrayed 2${\times}$2 digital optical switches (DOSs) and 16${\times}$16 arrayed waveguide grating (AWG) routers. For these devices, we synthesized a polyetherimide-disperse red 1 (PEI-DR1) side chain NLO polymer and a low-loss optical polymer known as fluorinated polyaryleneethers (FPAE). This paper presents the details of our development of these polymeric photonic devices considering all aspects from materials to packaging.

• Journal of the Institute of Convergence Signal Processing
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• v.9 no.1
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• pp.39-45
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• 2008

This paper considers the multi-objective optimization of a multi-service arrayed waveguide grating-based single-hop WDM network with the two conflicting objectives of maximizing throughput while minimizing delay. This paper presents a genetic algorithm based methodology for finding the optimal throughput-delay tradeoff curve, the so-called Pareto-optimal frontier. Genetic algorithm based methodology provides the network architecture parameters and the Medium Access Control protocol parameters that achieve the Pareto-optima in a computationally efficient manner. The numerical results obtained with this methodology provide the Pareto-optimal network planning and operation solution for a wide range of traffic scenarios. The presented methodology is applicable to other networks with a similar throughput-delay tradeoff.

• 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.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.656-658
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• 1997

AWG designed in this paper is considered with flat passband characteristics in the channel as a method for solving frequency stability problems of the sources in the conventional optical filters. This device can acquire the flat passband characteristics by inserting the multimode wave guides utilizing the self imaging effec between input wave guides and first star coupler. BPM simulation results show that the excess loss is smaller than 6.5 dB, the crosstalk is less than -22 dB and the 1 dB passband is about 50 GHz in the central channel.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.12
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• pp.2828-2833
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• 1997

In this paepr, we have proposed an enhanced TDM with WDM hybrid photonic switching architecture, which has much simpler configuration and requires less hard ware. the basic module consists of arrayed waveguide grating (AWG) for wavelength division, compressor and fiber delay lines for time division. When compared with other systems, we proved that the proposed switch is suitable for large capacity photonic switching system due to less complexity and lower cost in implementation than the previous ones.

• ETRI Journal
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• v.38 no.1
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• pp.9-17
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• 2016

We demonstrate a time- and wavelength-division multiplexed passive optical network system employing a vertical-cavity surface-emitting laser array-based optical line terminal transceiver and a tunable bidirectional optical subassembly-based optical network terminal transceiver. A packet error-free operation is achieved after a 40 km single-mode fiber bidirectional transmission. We also discuss an arrayed waveguide grating, a photo detector array based on complementary metal-oxide-semiconductor photonics technologies, and low-cost key devices for deployment in access networks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.220-223
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• 2006

In this paper, we studied about the level controller of optical signal with 40 channels by 4 VOA(Variable Optical Attenuator) with 12 channels. Total 8 microprocessors control 40 chamois for control of optical signal level so that a microprocessor controls 5 channels each. Moreover a microprocessor was added to communicate with outside and transfer instruction to each microprocessor. The output optical signal is measured and VOA is controlled as a result of it. The VOA outputs is inputted into PD(Photo Detector) at once. We could control multi-channel optical signals simply like this.