Browsing by Author "Shih, F. Y."

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10 Gb/s TDM passive optical networks using four wavelengths multiplexed channels
(2009-07-01)
Wang, C. H.
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Shih, F. Y.
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Yeh, C. H.
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Chow, C. W.
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Chi, S.
We propose a new architecture for 10 Gb/s upstream traffic in TDM-PON using externally injection-locked Fabry-Perot laser diodes (FP-LDs) in each optical network unit (ONU). Four directly modulated 2.5 Gb/s FP-LDs were injection-locked by continuous wave (CW) carriers distributed from the optical line terminal (OLT). Hence, a total of 10 Gb/s upstream traffic can be achieved. Experimental results show negligible power penalty at a transmission of 25 km standard single mode fiber (SMF) without dispersion compensation. The performance of the injection-locked FP-LD is also studied. (C) 2009 Elsevier B.V. All rights reserved.
10 Gb/s Uplink Traffic Transmitter Using External Optical Injection for TDM Passive Optical Networks
(2009)
Wang, C. H.
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Shih, F. Y.
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Yeh, C. H.
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Chow, C. W.
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Chi, S.
We propose and demonstrate an upgrade solution for 10-Gb/s TDM-PON using four directly-modulated 2.5-Gb/s FP-LDs in each ONU. The performance of the proposed scheme is analyzed, showing its feasibility for the next-generation 10-Gb/s networks. (C) 2009 Optical Society of America
A self-protected colorless WDM-PON with 2.5 Gb/s upstream signal based on RSOA
(2008-08-04)
Yeh, C. H.
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Chow, C. W.
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Wang, C. H.
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Shih, F. Y.
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Chien, H. C.
In this investigation, we propose and demonstrate a colorless wavelength division multiplexed passive optical network (WDM-PON) at 2.5 Gb/s using reflective semiconductor optical amplifier (RSOA)-based optical networking units (ONUs); together with a self-protected architecture against fiber fault. In the optical line terminal (OLT), we use an array of self-seeding Fabry-Perot laser diodes (FP-LDs) to provide single-longitudinal-mode (SLM) continuous wave (CW) optical sources for the external injection to the RSOA-based ONUs. The self-survivable function for protecting the fiber fault in the distributed fibers and the proposed network performance are investigated and discussed. (C) 2008 Optical Society of America.
Adaptive upstream rate adjustment by RSOA-ONU depending on different injection power of seeding light in standard-reach and long-reach PON systems
(2012-08-01)
Yeh, C. H.
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Chow, C. W.
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Shih, F. Y.
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Pan, C. L.
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光電工程學系
The wavelength division multiplexing-time division multiplexing (WDM-TDM) passive optical network (PON) using reflective semiconductor optical amplifier (RSOA)-based colorless optical networking units (ONUS) is considered as a promising candidate for the realization of fiber-to-the-home (FTTH). And this architecture is actively considered by Industrial Technology Research Institute (ITRI) for the realization of FTTH in Taiwan. However, different fiber distances and optical components would introduce different power budgets to different ONUs in the PON. Besides, due to the aging of optical transmitter (Tx), the power decay of the distributed optical carrier from the central office (CO) could also reduce the injection power into each ONU. The situation will be more severe in the long-reach (LR) PON, which is considered as an option for the future access. In this work, we investigate a WDM-TDM PON using RSOA-based ONU for upstream data rate adjustment depending on different continuous wave (CW) injection powers. Both standard-reach (25 km) and LR (100 km) transmissions are evaluated. Moreover, a detail analysis of the upstream signal bit-error rate (BER) performances at different injection powers, upstream data rates, PON split-ratios under stand-reach and long-reach is presented. (C) 2012 Elsevier B.V. All rights reserved.
An Optical Switch-Based Self-Restored WDM-PON Architecture against Fiber Faults
(2011-01-01)
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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Chi, S.
In this paper, we propose and experimentally demonstrate a simple self-restored architecture for WDM passive optical network (PON) by only adding a novel 2x2 optical switch design in each optical networking unit (ONU). By using the proposed protection architecture, the affected traffic will be restored immediately against fiber fault in the feeder and distributed fibers. Moreover, the performance of proposed self-survivable WDM-PON is also discussed and analyzed.
Bidirectional ROF Transmission and Signal Remodulation Using Separate Optical Clock Distribution to Mitigate Signal Distortions
(2009)
Chow, C. W.
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Xu, L.
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Yeh, C. H.
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Wang, C. H.
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Shih, F. Y.
We demonstrate a bidirectional ROF system using a separate optical-clock distribution to mitigate signal-fading and code time-shifting. Error-free signal remodulation using downlink DPSK and uplink OOK was achieved in a 20-km reach ROF system. (C)2009 Optical Society of America
Characterization of Rayleigh backscattering performance of CS-SSB signal in carrier distributed passive optical network
(2011-06-15)
Wang, C. H.
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Yeh, C. H.
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Chow, C. W.
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Wu, Y. F.
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Shih, F. Y.
Rayleigh backscattering (RB) is an intrinsic phenomenon when light propagating in fiber and its level is fixed by the fiber type and the network configuration used. Thus. RB noise would be one of the major impairments in a carrier distributed passive optical network (PON). Previously demonstrated carrier suppressed subcarrier-amplitude modulated phase shift keying (CSS-AMPSK) modulation may be useful to effectively mitigate the RB noise. However, this modulation is basically a carrier suppressed double sidebands modulation (CS-DSB) format, in which the same information is carried by the two sidebands with equal magnitude. This is not very power-efficient for PON. Here, we further extend our RB studies by using carrier suppressed single sideband non-return-to-zero (CS-SSB-NRZ) modulation. We experimentally characterize the CS-SSB-NRZ modulation when subjected to both contributions of RB: Carrier-RB and Signal-RB. Then, numerical simulations are performed, and the results are in good match with the experiment. Finally, upstream transmission experiment is performed showing the feasibility of using the CS-SSB-NRZ signal for the carrier distributed PON. The RB performance of the SSB-NRZ signals transmitted at different distances and driven at different radio-frequency (RF) f(s) is also investigated. (C) 2011 Elsevier B.V. All rights reserved.
Demonstration of High Spectral Efficient OFDM-QAM Long Reach Passive Optical Network
(2008)
Chow, C. W.
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Yeh, C. H.
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Wang, C. H.
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Shih, F. Y.
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Lin, Y. M.
We demonstrate a high spectral-efficient LR-PON using 4Gb/s OFDM-QAM for both up-and-downstream, achieving a high split-ratio 256, using optical components optimized for GPON.
Demonstration of Signal Remodulation Long Reach Carrier Distributed Passive Optical Network using OFDM-QAM Signal
(2009)
Chow, C. W.
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Yeh, C. H.
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Wang, C. H.
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Shih, F. Y.
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Chi, S.
OFDM is a promising candidate for LR-PON. We study the possibility of using OFDM for signal remodulation in the LR-PON. Three different colorless ONU architectures are tested and compared.
Dual-Wavelength S-Band Erbium-Doped Fiber Double-Ring Laser
(2008-12-01)
Yeh, C. H.
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Shih, F. Y.
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Chow, C. W.
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Chi, S.
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光電工程學系
We propose and demonstrate an S-band CW dual-wavelength erbium-doped fiber (EDF) dual-ring laser using a compound-ring filter (CRF) with various coupling losses inside the gain cavity. Employing a ring filter combined within the cavity, the fiber laser can lase a dual wavelength without any filter inside the ring loop. The dual-wavelength output exhibits a good performance having optical side-mode suppression ratios (SMSRs) of 31.6 and 31.8 dB and output powers of -9.6 and -9.3 dBm at 1505.58 and 1506.43 nm, respectively, when the coupling loss is 30% inside the cavity. In addition, the output stabilities of the dual-wavelength laser have also been analyzed.
Employing external injection-locked Fabry-Perot laser scheme for mm-wave generation
(2011-04-01)
Wu, Y. F.
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Yeh, C. H.
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Chow, C. W.
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Shih, F. Y.
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Chi, S.
We propose and experimentally investigate a 170 GHz band millimeter-wave source employing an external dual-mode-locked Fabry-Perot laser diode (FP-LD) with a 1.38 nm mode-spacing. Two continuous-wave (CW) lights are aligned to inject the corresponding modes of FP-LD to generate dual-beat-mode output. The proposed dual-mode laser is not only stable, but also has single-longitudinal-mode (SLM) output characteristics. Moreover, the relationship between two external-injected wavelengths is also analyzed for the dual-wavelength output.
Fabry-Perot Laser Based Wavelength Converter without External Injection
(2009)
Yeh, C. H.
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Chow, C. W.
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Wang, C. H.
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Shih, F. Y.
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Wu, Y. F.
We propose an all optical wavelength converter using a multi-longitudinal-mode Fabry-Perot laser diode without any external probe beam or external build-in cavity. The proposed converter apparatus is simple and cost-effective for WDM network applications.
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.
Mitigation of Signal Distortions Using Reference Signal Distribution With Colorless Remote Antenna Units for Radio-Over-Fiber Applications
(2009-11-01)
Chow, C. W.
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Xu, L.
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Yeh, C. H.
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Wang, C. H.
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Shih, F. Y.
In this paper, we propose and demonstrate a bidirectional radio-over-fiber (ROF) system using a reference signal distribution. In order to minimize the radio-frequency (RF) signal attenuation as well as limit the transmit power to moderate levels, small cell size, or picocell is used in the ROF system. This will result in the need of many base stations (BSs) to provide sufficient network coverage. Because of this, colorless remote antenna unit (RAU) with optical carrier generated and distributed from the head end (HE) is employed. Experimental results show that error-free signal transmission and remodulation using downstream differential phase shift keying (DPSK) and upstream ON-OFF keying (OOK) is achieved in a 20-km reach ROF system. Experimental characterization of the reflective semiconductor optical amplifier (RSOA)-based remodulation unit is also performed. Numerical simulation is performed to compare the proposed scheme with several conventional optical millimeter-wave (mm-wave) schemes, including double sideband (DSB), optical carrier suppression (OCS), and single sideband (SSB). Results show that the proposed scheme could be a potential candidate to mitigate signal distortions due to signal fading and code time shifting.
Multiwavelength erbium-doped fiber ring laser employing Fabry-Perot etalon inside cavity operating in room temperature
(2009-08-01)
Yeh, C. H.
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Chow, C. W.
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Wu, Y. F.
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Shih, F. Y.
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Wang, C. H.
In this investigation, we propose and demonstrate a simple and cost-effective erbium-doped fiber (EDF) ring laser using a Fabry-Perot etalon inside a linear cavity and employing the accurate fiber cavity length to satisfy the least common multiple number for generating multiwavelength in C-band at room temperature. Furthermore, the center wavelength of the lasing wavelength bands can be adjusted to 1541.02, 1551.32, and 1562.03 nm, respectively. The wavelength separation in each wavelength band is 0.34 nm. Moreover, the output stability of the multiwavelength laser has also been discussed and analyzed. (C) 2009 Elsevier Inc. All rights reserved.
Performance and Limitation of Radio-over-Fiber Network Using Standard WiMAX Signal
(2009)
Yeh, C. H.
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Chow, C. W.
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Shih, F. Y.
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Wang, C. H.
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Wu, Y. F.
WiMAX is considered for the last mile wireless connectivity to provide flexible broadband services to end users. And Radio over Fiber (RoF) system has attracted industry and research interest to extend the wireless cell coverage and reduce the cost by using the distributed remote antenna units (RAUs). Here, the performance of WiMAX RoF system will be characterized. Results show that the effective RoF transmission fiber length can be limited due to the time division duplex (TDD) framing in the connection using standard WiMAX signal generated by a commercial WiMAX bias station. WiMAX RoF performances of throughput and packet-loss at different link lengths are investigated and analyzed. Besides, a robust TDD switch architecture used in each RAU will be proposed for the WiMAX RoF system.
Rayleigh Backscattering Circumvention in Ring-Based Access Network Using RSOA-ONU
(2011-08-15)
Chow, C. W.
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Yeh, C. H.
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Wu, Y. F.
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Lin, Y. H.
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Shih, F. Y.
We propose and demonstrate a Rayleigh backscattering (RB) interferometric beat noise circumvention architecture for the ring-based wavelength-division-multiplexed (WDM) access networks. RB can be significantly avoided since the RB and the upstream signal are traveling in opposite directions. We also analyze the performance of the proposed scheme for upgrading to 40 Gb/s and the influence of wavelength-drift at the remote node (RN).
Rayleigh Backscattering Performance of OFDM-QAM in Carrier Distributed Passive Optical Networks
(2008-11-01)
Chow, C. W.
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Yeh, C. H.
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Shih, F. Y.
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Chi, S.
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光電工程學系
The passive optical network (PON) using an orthogonal frequency-division-multiplexing (OFDM) format is a subject of many research works recently. Due to the high spectral efficiency, low bandwidth optical components can be used in this OFDM-PON. We quantify, for the first time, the performance of the OFDM signal when subjected to the noise generated by the two components of the Rayleigh backscattering (RB): carrier generated RB (carrier-RB) and signal generated RB (signal-RB) that are present in the carrier-distributed PONs. An RB comparison between OFDM quadrature amplitude modulation and nonreturn-to-zero is preformed.
Self-protected time-division-multiplexed passive access networks in tree and ring topology architectures
(2012-04-01)
Yeh, C. H.
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Chow, C. W.
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Wu, Y. F.
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Shih, F. Y.
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Chi, S.
In this investigation we propose and experimentally demonstrate the self-protected and survivable time-division-multiplexed passive optical networks (PONs) in tree and ring topology architectures against fiber fault. Here, the feasible protection access architectures for the tree- and ring-based PONs are studied and discussed. Furthermore, different scenarios of fault locations, such as in the feeder fiber and distribution fiber, are also studied in the optical distributed networks.
Self-protection multi-ring-architecture fiber sensing system
(2008)
Wang, C. H.
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Yeh, C. H.
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Shih, F. Y.
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Chow, C. W.
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Hsu, K. C.
In this investigation, we propose and experimentally investigate a simply self-restored ring-based fiber Bragg grating (FBG) based sensor system. This proposed multi-ring passive sensing architecture is without any active components in the entire network. In this experiment, the network survivability and capacity for the multi-point sensor systems are also enhanced. Besides, the tunable laser source (TLS) is adopted in central office (CO) for FBG sensing. The survivability of a eight-point FBG sensor is examined and analyzed. Due to the passive sensor network, the cost-effective and intelligent sensing system is entirely centralized by CO. As a result, the experimental results show that the proposed system can assist the reliable FBG sensing network for a large-scale and multi-point architecture.