Browsing by Author "Sung, J. Y."

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13 Gbit/s WDM-OFDM PON using RSOA-based colourless ONU with seeding light source in local exchange
(2011-10-27)
Chow, C. W.
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Yeh, C. H.
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Wu, Y. F.
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Chen, H. Y.
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Lin, Y. H.
Optical-carrier-distribution using reflective-semiconductor-optical-amplifier (RSOA)-based colorless optical-networking-unit (ONU) is a promising candidate for the wavelength-division-multiplexed passive-optical-network (WDM-PON). However, commercial available RSOA has a typical modulation-bandwidth of similar to 1 GHz, which is not enough for the future bandwidth demand. Here we demonstrate a WDM-PON using 1 GHz bandwidth RSOA-based ONU, which can be operated up to 13 Gbit/s. Experimental results show that 20 km singlemode-fibre transmission of the 13 Gbit/s orthogonal-frequency-division-multiplexed (OFDM) signal can be achieved with bit-error rate lower than the forward error correction threshold.
2.5-10 Gbit/s laser source based on two optical-injection Fabry-Perot laser diodes
(2013-12-01)
Wu, Y. F.
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Yeh, C. H.
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Chow, C. W.
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Liu, Y. L.
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Sung, J. Y.
In this investigation, a wavelength tunable laser source based on optical-injection of two Fabry-Perot laser diodes (FP-LDs) is demonstrated. In the proposed laser source, a self-injection locked master FP-LD provides a stable continuous-wave (CW) lasing, which wavelength can be selected by means of an optical tunable bandpass filter (TBF). The CW wavelength is launched into another FP-LD (the slave laser) for direct signal modulation. In this two optical-injection FP-LD architecture, directly modulation of 2.5 Gbit/s on-off keying (OOK) and 10 Gbit/s orthogonal frequency division multiplexing (OFDM) signals can be achieved in the proposed laser source with negligible power penalty after 25 km single-mode-fiber (SMF) transmission. (C) 2013 Elsevier Inc. All rights reserved.
A Convergent Wireline and Wireless Time-and-Wavelength-Division-Multiplexed Passive Optical Network
(2015-06-01)
Chow, C. W.
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Sung, J. Y.
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Yeh, C. H.
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光電工程學系
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光電工程研究所
We propose and demonstrate a convergent wireline and wireless access network using time-and-wavelength-division-multiplexed passive optical network (TWDM-PON) architecture. Bidirectional 40-km single-mode-fiber transmissions (including the 60-GHz wireless transmission) satisfying the forward error correction limit are demonstrated, with data rates of similar to 10 Gb/s per wavelength in the downstream signal and 17.50 Gb/s per wavelength in the upstream signal. To achieve higher data rate, bit-loading orthogonal frequency-division modulation was used. We also analyze the laser-linewidth-induced performance variation to the signal generated by optical beating and the baseband signal.
A PRACTICAL IN-HOME ILLUMINATION CONSIDERATION TO REDUCE DATA RATE FLUCTUATION IN VISIBLE LIGHT COMMUNICATION
(2015-04-01)
Chow, C. W.
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Liu, Y.
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Yeh, C. H.
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Sung, J. Y.
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Liu, Y. L.
Visible light communication based on LED has attracted more and more attention. As the primary function of LED luminaries is optimized for lighting and illumination, it challenges the communication properties of VLC. An investigation based on different in-home illumination conditions using commercially available white-light LED luminaries to optimize both illumination and communication is highly desirable. In this work, we investigate joint illumination and communication systems to provide an in-home lighting and VLC system. We first focus on the performance constraints set by illumination properties and discuss lighting conditions using different kinds of commercially available luminaries, beam angles, and LED lamp arrangements, and consider reflections off different wall materials. Then we propose and experimentally demonstrate a white-light phosphor-based LED adaptive data rate VLC system. Finally, the achievable data rates of a joint illumination and VLC system are discussed based on the experimental results, and an environment with reduced VLC data rate fluctuation can be achieved.
A scalable and continuous-upgradable optical wireless and wired convergent access network
(2014-06-02)
Sung, J. Y.
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Cheng, K. T.
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Chow, C. W.
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Yeh, C. H.
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Pan, C. -L.
In this work, a scalable and continuous upgradable convergent optical access network is proposed. By using a multi-wavelength coherent comb source and a programmable waveshaper at the central office (CO), optical millimeter-wave (mm-wave) signals of different frequencies (from baseband to > 100 GHz) can be generated. Hence, it provides a scalable and continuous upgradable solution for end-user who needs 60 GHz wireless services now and > 100 GHz wireless services in the future. During the upgrade, user only needs to upgrade their optical networking unit (ONU). A programmable waveshaper is used to select the suitable optical tones with wavelength separation equals to the desired mm-wave frequency; while the CO remains intact. The centralized characteristics of the proposed system can easily add any new service and end-user. The centralized control of the wavelength makes the system more stable. Wired data rate of 17.45 Gb/s and w-band wireless data rate up to 3.36 Gb/s were demonstrated after transmission over 40 km of single-mode fiber (SMF). (C) 2014 Optical Society of America
Bend and twist insensitive large core multimode fiber (LCMMF) for baseband and ROF in-home data transmission
(2013-05-01)
Chow, C. W.
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Yeh, C. H.
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Yang, L. G.
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Sung, J. Y.
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Huang, S. P.
To extend the fiber access network into the home, using optical fiber is a good choice. Bend and twist insensitive optical fiber with a large core diameter is particularly attractive, since it is easy to install and connectorize. However, its bandwidth will be severely limited by its large multimodal dispersion. Here, we first reported the design and fabrication of a novel bend and twist insensitive, 80-mu m core-diameter large-core multimode fiber (LCMMF) for in-home data communication. We experimentally demonstrated 10 Gb/s multiple bands data transmission at distances for residential buildings and data centers. The bit-error-rate (BER) performances of the LCMMF under bending and twisting were evaluated. Finally, we also discovered experimentally an important relation between the differential-mode-delay (DMD) and the BER of the fabricated LCMMF. This relationship could be a valuable tool for fiber manufacturers. (C) 2012 Elsevier B.V. All rights reserved.
Coding for stable transmission of W-band radio-over-fiber system using direct-beating of two independent lasers
(2014-10-20)
Yang, L. G.
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Sung, J. Y.
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Chow, C. W.
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Yeh, C. H.
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Cheng, K. T.
We demonstrate experimentally Manchester (MC) coding based W-band (75 - 110 GHz) radio-over-fiber (ROF) system to reduce the low-frequency-components (LFCs) signal distortion generated by two independent low-cost lasers using spectral shaping. Hence, a low-cost and higher performance W-band ROF system is achieved. In this system, direct-beating of two independent low-cost CW lasers without frequency tracking circuit (FTC) is used to generate the millimeter-wave. Approaches, such as delayed self-heterodyne interferometer and heterodyne beating are performed to characterize the optical-beating-interference sub-terahertz signal (OBIS). Furthermore, W-band ROF systems using MC coding and NRZ-OOK are compared and discussed. (C) 2014 Optical Society of America
Demonstration of using injection-locked Fabry-Perot laser diode for 10 Gbit/s 16-QAM OFDM WDM-PON
(1970-01-01)
Yeh, C. H.
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Chow, C. W.
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Chen, H. Y.
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Sung, J. Y.
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Liu, Y. L.
"A 10 Gbit/s OFDM upstream transmission has been investigated by using a Fabry-Perot laser diode (FP-LD) based ONU with seeding-light in a colourless WDM-PON. Also demonstrated is the relationship of CW injection power and SNR of each OFDM subcarrier for a modelocked FP-LD. Moreover, when a 16-QAM OFDM modulation is applied in a modelocked FP-LD, -15.7 dBm received sensitivity at the BER of 3.8 x 10(-3) can be obtained after 20 km fibre transmission."
Demonstration of using multi-band 16-QAM OFDM modulation with direct-detection in 10 GHz bandwidth for 37.3-Gb/s PON
(2014-02-01)
Yeh, C. H.
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Chen, H. Y.
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Chow, C. W.
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Sung, J. Y.
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光電工程學系
We propose and experimentally demonstrate a 37.3 Gb/s passive optical network using four-band orthogonal-frequency-division-multiplexing (OFDM) channels within 10 GHz bandwidth. Here, the required sampling rate and resolution of digital-to-analog/analog-to-digital (DA/AD) converter are only 5 GS/s and 8 bits to accomplish the 40 Gb/s OFDM downstream rate. Moreover, to reduce the power fading and fiber chromatic dispersion issues, a 0.7 chirp parameter Mach-Zehnder modulator is used for the four-band OFDM modulation scheme. Downstream negative power penalty of 0.37 dB can be obtained at the bit error rate of after 20 km standard single mode fiber transmission without dispersion compensation.
Dual-reflected-structure erbium-doped fiber laser in single-longitudinal-mode for wavelength-tuning
(2012-05-01)
Yeh, C. H.
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Chow, C. W.
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Sung, J. Y.
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Lu, S. S.
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Wu, Y. F.
In this work, we propose and demonstrate a dual-reflected-structure erbium-doped fiber (EDF) laser with a linear cavity using a passive saturable-absorbor-based (SAB) filter to achieve single-longitudinal-mode (SLM) lasing. Here, we can observe the wavelength tuning range between 1530.0 and 1562.0 nm with the output powers of -13.7 to -7.6 dBm and optical signal to noise ratios (OSNRs) of 35.4 and 47.9 dB/0.05 nm, respectively. Moreover, when the lasing wavelength is tuned to the longer wavelength gradually, the obtained output power and SNR increase. This is because the Er+ gain can be suppressed and moves to the longer wavelength via the proposed fiber laser structure. In addition, the output stability of the proposed laser has also been analyzed and studied.
Enabling Technologies and Signal Processing for NG-PON2 and Future WDM-PON (Invited)
(2013-01-01)
Chow, C. W.
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Sung, J. Y.
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Hsu, C. W.
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Yeh, C. H.
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光電工程學系
Silicon-based optical components are now mature technologies; and they can be used in the time-and-wavelength-division-multiplexed passive-optical-network (TWDM-PON) optical networking unit (ONU)to increase the level of integration for cost reduction. We will also discuss the further migration form the NG-PON2 to the future pure WDM-PON.
Fiber-fault protection WDM-PON using new apparatus in optical networking unit
(2012-04-01)
Yeh, C. H.
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Chow, C. W.
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Shih, F. Y.
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Wu, Y. F.
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Sung, J. Y.
In this study, we propose and experimentally demonstrate a simple self-protection architecture for WDM passive optical network (PUN) by adding a novel 2x2 optical switch design in each optical networking unit (ONU). Two adjacent ONUs are interconnected into a group. By using the proposed protection architecture, the affected traffic can be restored immediately against fiber fault in the feeder and distributed fibers. Moreover, the performance of proposed self-protection WDM-PON is also discussed and analyzed. (C) 2011 Elsevier B.V. All rights reserved.
Hybrid OFDM-based multi-band wireless and baseband signal transmission in PON access
(2012-03-29)
Yeh, C. H.
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Chow, C. W.
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Chen, H. Y.
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Sung, J. Y.
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光電工程學系
A hybrid OFDM-baseband (BB) signal and three-band OFDM wireless channels using the 2.5 GHz bandwidth directly modulated laser and 10 GHz bandwidth electroabsorption modulated laser in a passive optical network (PON) is investigated. Each 16-QAM OFDM wireless and 64-QAM OFDM-BB signals can achieve 11.2 and 15 Gbit/s traffic data rates, respectively, in 20 km fibre transmissions. Moreover, the network performance has also been analysed and discussed.
Integrated SOT-based Receiver Module for TWDM-PON
(2016)
Hsu, Y.
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Wu, X. R.
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Wei, L. Y.
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Xu, K.
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Hsu, C. W.
We demonstrate a SOl-based integrated receiver (Rx) module for the TWDM-PON. The downstream can be de-multiplexed by a tunable de-multiplexer using cascaded silicon-micro-ring and each channel is received by germanium-on-silicon photodiode.
Low bending loss square-core optical fiber for optical communication
(2015-01-01)
Liu, P. F.
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Sung, J. Y.
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Chow, C. W.
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Yeh, C. H.
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Chou, Gary
In this work, we propose and demonstrate a single-mode square-core optical fiber for optical communications. In the proposed square-core single-mode-fiber (SC-SMF), high bandwidth-distance product and low bending loss can be achieved. In this paper, first of all, we discuss the single mode condition of the SC-SMF theoretically and numerically. Then, we discuss the fabrication of the SC-SMF. We also characterize the performances of the proposed SC-SMF, such as the bending loss, and compare it with the standard single mode fiber (SSMF). A 10 Gb/s transmission experiment using 200 m, 500 m and 1 km SC-SMFs are performed. Negligible power penalty is observed.
OFDM RF power-fading circumvention for long-reach WDM-PON
(2014-10-06)
Chow, C. W.
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Yeh, C. H.
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Sung, J. Y.
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光電工程學系
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光電工程研究所
We propose and demonstrate an orthogonal frequency division multiplexing (OFDM) radio-frequency (RF) power-fading circumvention scheme for long-reach wavelength-division-multiplexed passive-optical-network (LR-WDM-PON); hence the same capacity of 40 Gb/s can be provided to all the optical-networking-units (ONUs) in the LR-WDM-PON. Numerical analysis and proof-of-concept experiment are performed. (C) 2014 Optical Society of America
Optical filter analyses for demultiplexing all-optical OFDM transmission systems
(2015-08-01)
Sung, J. Y.
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Hsu, C. W.
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Su, H. Q.
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Chow, C. W.
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Yeh, C. H.
Using a single optical filter to demultiplex the all-optical orthogonal frequency-division multiplexing (OFDM) system was regarded as cost-effective and simple. Here, an all-optical OFDM signal demultiplexer using sinc transfer function was analyzed. The performance difference for using optical demultiplexers with different transfer functions was also compared and discussed. Within 20 km transmission, the sinc optical filter providing orthogonality between neighbor optical subcarriers can improve the signal performance by reducing the inter-carrier interference. After 20 km transmission, the signal performance degradation may mainly be dominated by dispersion for 10 Gb/s channel capacity; hence the advantage of sinc filter becomes negligible. These analyses provide the idea for how to choose the optical demultiplexer to integrate the whole optical fast Fourier transform circuit and optical sampling circuit into a single filter. This can effectively reduce the system cost and complexity.
Ring-Based WDM Access Network Providing Both Rayleigh Backscattering Noise Mitigation and Fiber-Fault Protection
(2012-10-15)
Yeh, C. H.
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Chow, C. W.
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Huang, S. P.
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Sung, J. Y.
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Liu, Y. L.
In this paper, we propose and investigate a ring-based wavelength-division-multiplexing passive optical network (WDM-PON) providing both Rayleigh backscattering (RB) noise mitigation and fiber-fault protection. The proposed ring-based WDM-PON has a dual-ring architecture to protect and restore any fiber fault. Besides, the ring architecture also can mitigate the RB beat noise, since the RB and the upstream wavelengths are propagating in opposite directions. Here, we discuss and analyze the characteristics of the downstream signals using 10 Gb/s ON-OFF keying (OOK), 10 Gb/s differential phase-shift keying, and 10 Gb/s orthogonal frequency-division multiplexing (OFDM) modulations, respectively. Moreover, we also investigate the upstream traffic using the 2.5 Gb/s OOK and 10 Gb/s OFDM generated by the directly modulated reflective semiconductor optical amplifier-based optical network unit, respectively.
Scalable OFDM TWDM-PON using Silicon-based Photonic Devices and Wavelength Tunable Upstream Transmitter
(2014-01-01)
Sung, J. Y.
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Chow, C. W.
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Yeh, C. H.
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Xu, K.
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Tsang, H. K.
We propose and demonstrate a scalable time-wavelength-division-multiplexed passive-optical-network (TWDM-PON) using tunable silicon-micro-ring (SMR) and Ge-Si photodiode as downstream receiver; and wavelength tunable reflective-semiconductor-optical-amplifier (RSOA) ring laser as upstream transmitter.
Square-core single-mode-fiber (SC-SMF) with high bending tolerance for data center networks
(2015-08-15)
Chow, C. W.
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Huang, S. P.
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Yeh, C. H.
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Sung, J. Y.
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Liu, P. F.
Square-core optical fiber has been proposed recently for high optical power delivery in industrial processing tools with core size larger than 400 x 400 mu m(2). In this work, we first study the possibility of significantly reducing the core side to single-mode condition (i.e. 9 x 9 mu m(2)) at optical communication wavelength. In the proposed square-core single-mode-fiber (SC-SMF), high bandwidth-distance product and low bending loss are achieved. We also discuss the fabrication of the SC-SMF. After this, the bending losses of the SC-SMF and standard single mode fiber (SSMF) are analyzed and compared. Finally, 10 Gb/s signal transmission using conventional on-off keying (OOK) and orthogonal frequency division multiplexing (OFDM) passing through 200 m, 500 m and 1 km SC-SMFs are performed. Negligible power penalty is observed. We believe that this can be another choice of high bending tolerance fiber which is simple to manufacture. (C) 2015 Elsevier B.V. All rights reserved.