Browsing by Author "Wu, Y. F."

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100 GHz ultra-wideband (UWB) fiber-to-the-antenna (FTTA) system for in-building and in-home networks
(2010-01-18)
Chow, C. W.
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Kuo, F. M.
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Shi, J. W.
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Yeh, C. H.
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Wu, Y. F.
Fiber-to-the-antenna (FTTA) system can be a cost-effective technique for distributing high frequency signals from the head-end office to a number of remote antenna units via passive optical splitter and propagating through low-loss and low-cost optical fibers. Here, we experimentally demonstrate an optical ultra-wideband (UWB) - impulse radio (IR) FTTA system for in-building and in-home applications. The optical UWB-IR wireless link is operated in the W-band (75 GHz - 110 GHz) using our developed near-ballistic unitraveling-carrier photodiode based photonic transmitter (PT) and a 10 GHz mode-locked laser. 2.5 Gb/s UWB-IR FTTA systems with 1,024 high split-ratio and transmission over 300 m optical fiber are demonstrated using direct PT modulation. (C) 2010 Optical Society of America
100 GHz Ultra-wideband Wireless System for the Fiber to the Antenna Networks
(2010)
Chow, C. W.
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Kuo, F. M.
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Shi, J. W.
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Yeh, C. H.
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Wu, Y. F.
We experimentally demonstrate an optical ultra-wideband (UWB) (75GHz-110GHz) fiber-to-the-antenna (FTTA) system using our developed W-band near-ballistic unitraveling-carrier photodiode (NBUTC-PD) based photonic transmitter (PT). 2.5Gb/s and 1.5Gb/s UWB-FTTA systems with 1,024 high split-ratio are demonstrated. (C)2010 Optical Society of America
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.
An energy-efficient tie-type architecture for stable and wavelength-tunable SOA-based fiber laser
(2012-10-01)
Yeh, C. H.
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Chow, C. W.
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Wu, Y. F.
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Lu, S. S.
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光電工程學系
A new and energy-efficient tie-type architecture for stable and wavelength-tunable semiconductor optical amplifier (SOA)-based fiber ring laser is proposed and experimentally investigated. Here, the tie-type laser configuration is constructed by two Sagnac fiber loops. The proposed laser also can extend the lasing wavelength to longer wavelength (L-band) even only the C-band SOA is used. The proposed tie-type architecture has > 5 dB higher output optical power at bias current of 80 mA when compared with the single ring SOA-based fiber laser. In this measurement, the output power, wavelength tuning range, side-mode suppression ratio (SMSR) and output stability of proposed fiber laser have also been analyzed and discussed. (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.
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.
Demonstrations of 10 and 40 Gbps upstream transmissions using 1.2 GHz RSOA-based ONU in long-reach access networks
(2012-03-01)
Yeh, C. H.
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Chow, C. W.
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Wu, Y. F.
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Chen, H. Y.
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光電工程學系
Carrier-distributed long-reach passive optical network (LR-PON) is a promising candidate for future access networks. In this work, we analyze and compare the 4 x 2.5 Gb/s and 4 x 10 Gb/s upstream traffics in a carrier-distributed LR-PON using four wavelength-multiplexed 2.5 Gb/s on-off keying (OOK) and 10 Gb/s optical orthogonal frequency division multiplexing-quadrature amplitude modulation (OFDM-QAM) signals. Four commercial 1.2 GHz bandwidth reflective semiconductor optical amplifiers (RSOAs) are used in each optical networking unit (ONU) for the generation of the upstream signal. Due to the limited bandwidth of the RSOA, only up to 2.5 Gb/s upstream OOK signal can be generated. However, by using the spectral efficient modulation, such as OFDM-QAM, 10 Gb/s data rate can be achieved. 20, 50 and 75 km fiber transmissions are also compared using the two different kinds of modulation respectively. (C) 2011 Elsevier Inc. All rights reserved.
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.
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.
High-Speed Phosphor-LED Wireless Communication System Utilizing No Blue Filter
(2014-01-01)
Yeh, C. H.
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Chow, C. W.
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Chen, H. Y.
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Chen, J.
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Liu, Y. L.
In this paper, we propose and investigate an adaptively 84.44 to 190 Mb/s phosphor-LED visible light communication (VLC) system at a practical transmission distance. Here, we utilize the orthogonal-frequency-division-multiplexing quadrature-amplitude-modulation (OFDM-QAM) modulation with power/bit-loading algorithm in proposed VLC system. In the experiment, the optimal analogy pre-equalization design is also performed at LED-Tx side and no blue filter is used at the Rx side for extending the modulation bandwidth from 1 MHz to 30 MHz. In addition, the corresponding free space transmission lengths are between 75 cm and 2 m under various data rates of proposed VLC. And the measured bit error rates (BERs) of < 3.8x10(-3) [forward error correction (FEC) limit] at different transmission lengths and measured data rates can be also obtained. Finally, we believe that our proposed scheme could be another alternative VLC implementation in practical distance, supporting > 100 Mb/s, using commercially available LED and PD (without optical blue filtering) and compact size.
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).
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.
Stable Multiwavelength Semiconductor Laser Using FWM and SBS-Assisted Filter
(2011-11-01)
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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Chen, J. H.
A stable and flattened quadruple-wavelength laser system is proposed and experimentally investigated. The laser consists of an external injection Fabry-Perot laser diode (FP-LD) and a stimulated-Brillouin-scattering (SBS)-assisted filter. In the measurement, the power difference (Delta P) of the lasing quadruple-wavelength can be enhanced within 2.0 dB by SBS-assisted filtering after 22-km single-mode fiber (SMF) propagation. In addition, we can change the two injected wavelengths for tuning the quadruple-wavelength. Besides, the output stability of the proposed laser has been studied and analyzed.
Stable wavelength-tuning laser in single-frequency by optical-injected Fabry-Perot laser diode and RSOA for long fiber distance propagation
(2012-01-01)
Yeh, C. H.
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Chow, C. W.
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Wu, Y. F.
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Lu, S. S.
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Lin, Y. H.
In this demonstration, we propose and experimentally investigate a stable wavelength-tuning laser configuration by using self-seeded Fabry-Perot laser diode (FP-LD) and external-injected reflective semi-conductor optical amplifier (RSOA). Here, this proposed laser can be tuned in the wavelength range of 1534.05 to 1553.00 nm with a 1.1 nm tuning-step. And the output powers and side-mode suppression ratios (SMSRs) are measured at -5.3 to 4.6 dBm and 31.2 to 50.1 dB/0.05 nm, respectively. And, the proposed laser also can be directly modulated at 2.5 Gb/s on-off keying (OOK) modulation format and propagates 75 km single-mode fiber (SMF) with no optical amplifier and dispersion compensation.
Two-Mode Semiconductor Laser for mm-Wave in Radio over Fiber Transmission
(2011-01-01)
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, an mm-wave RoF transmission link with dual beat-mode optical source is investigated. We demonstrate a 170 GHz band millimeter-wave source using an external dual-mode-locked Fabry-Perot laser diode (FP-LD) with a 1.38 nm mode-spacing. Two distributed feedback (DFB) lasers are used 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, we also investigate the relationship between two external-injected wavelengths for the dual-wavelength output.