Browsing by Author "Chi, S."

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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
40 GHz Phase Shifter based on Semiconductor Laser
(2008-04-10)
Peng, P. C.
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Wu, F. M.
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Lin, C. T.
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Chen, J. H.
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Kao, W. C.
This investigation experimentally demonstrates a 40 GHz phase shifter based on a semiconductor laser. The phase shift is achieved by adjusting the bias current and wavelength detuning. The device has an optical delay of 23 ps and a phase shift of about 331 degrees.
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.
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.
Analysis of the carrier-suppressed single-sideband modulators used to mitigate Rayleigh backscattering in carrier-distributed PON
(2011-05-23)
Chow, C. W.
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Wang, C. H.
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Yeh, C. H.
;
Chi, S.
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光電工程學系
By using the carrier-suppressed single-sideband (CS-SSB) modulation, the Rayleigh backscattering (RB) experienced by the uplink signal can be effectively mitigated due to the reduction of the spectral overlap between the uplink signal and the distributed optical carrier. In this work, we first introduce the theoretical analysis of the CS-SSB generation using the dual-drive MZM (DD-MZM)-based and a dual-parallel MZM (DP-MZM)-based optical networking units (ONUs). Due to the different modulation mechanisms of the two CS-SSB modulations, the frequency components of the generated CS-SSB signals are also different. The transmission performance and the dispersion tolerance of the uplink signals generated by the two CS-SSB modulators are also analyzed and discussed. (C) 2011 Optical Society of America
ANALYSIS OF TUNABLE FLAT DISPERSION OF GERMANIUM DOPED FIBER WITH LIQUID CLADDING
(2010-06-01)
Liu, Y.
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Chen, N.
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Lai, Y.
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Chi, S.
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光電工程學系
We demonstrate numerically the tunable dispersion-flattened fibers can be achieved by immersing the Ge-doped fiber core in different liquid claddings. The dispersion slope can be flattened over 1100-1700 nm, which is suitable for tunable supercontinuum,generation with pumping wavelength in fiber communication or other wavelength regions. Finally. we demonstrate the feasibility, to fabricate the proposed structure with chemical etching method. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1357-1359, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25209
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
Carrier Distributed PON Using SSB-CS Signal for Rayleigh Backscattering Suppression
(2010)
Chow, C. W.
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Yeh, C. H.
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Liu, Y. F.
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Wang, C. H.
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Wu, C. L.
We demonstrate using single-sideband-carrier-suppressed (SSB-CS) signal to suppress the Rayleigh-Backscattering (RB) in a carrier-distributed PON. The SSB signal is generated by a dual-parallel Mach-Zehnder modulator (DP-MZM). The split-ratio and reach are also investigated and analyzed.
Characterization of Dark-Return-to-Zero Modulation Format at Different Transmitter and Receiver Bandwidths
(2008)
Wang, C. H.
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Chow, C. W.
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Yeh, C. H.
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Chi, S.
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光電工程學系
This work characterizes how the bandwidths of transmitter, receiver and optical filter affecting the quality of optical dark-return-to-zero (DRZ) signal. Optimum filtering bandwidths at Back-to-back (B2B) and 80km single mode fiber transmission are analyzed.
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.
Comparison of Two CS-SSB Modulators Used in Bidirectional Carrier Distributed Long-Reach Passive Optical Network
(2011)
Wang, C. H.
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Yang, L. G.
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Chow, C. W.
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Yeh, C. H.
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Chi, S.
Two different CS-SSB modulators based on Mach-Zehnder structure used in carrier-distributed long-reach passive optical networks are investigated and compared. The Rayleigh-backscattering beat noise tolerance and transmission performance are also discussed. (C) 2011 Optical Society of America
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.
Electrically Controlled Phase Shifter using Semiconductor Laser in Optical Single Sideband System
(2009)
Wu, F. M.
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Peng, P. C.
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Yeh, S. K.
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Lin, C. T.
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Chen, J. H.
This investigation experimentally explores a microwave phase shifter using a semiconductor laser in an optical single sidebancl system. The operational bandwidth from 12 to 20 GHz is achieved by adjusting the bias current.
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.
Fast and slow light property improvement in erbium-doped amplifier
(2013-01-01)
Peng, P. C.
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Wu, F. K.
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Kao, W. C.
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Chen, J.
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Lin, C. T.
This work experimentally demonstrates improvement of the fast light property in erbium-doped amplifiers at room temperature. The difference between the signal power and the pump power associated with bending loss is used to control the signal power at the different positions of the erbium-doped fiber (EDF) to improve the fast light property. Periodic bending of the EDF increases the time advance of the probe signal by over 288%. Additionally, this concept also could improve the fast light property using coherent population oscillations in semiconductor optical amplifiers.
FORMOSAT-3/COSMIC Constellation Spacecraft System Performance: After One Year in Orbit (vol 46, pg 3380, 2008)
(2009-04-01)
Fong, C. -J.
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Yang, S. -K.
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Chu, C. -H.
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Huang, C. -Y.
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Yeh, J. -J.