Browsing by Author "Yang, L. G."

Now showing 1 - 8 of 8

10 Gb/s optical carrier distributed network with W-band (0.1 THz) short-reach wireless communication system
(2012-10-01)
Chow, C. W.
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Yang, L. G.
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Yeh, C. H.
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Huang, C. B.
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Shi, J. W.
Millimeter-wave (mm-wave) operated in W-band (75 GHz-0.11 THz) is of particular interests, since this frequency band can carry signals at much higher data rates. We demonstrate a 10 Gb/s optical carrier-distributed network with the wireless communication system. The mm-wave signal at carrier frequency of 0.1 THz is generated by a high speed near-ballistic uni-traveling carrier photodiode (NBUTC-PD) based transmitter (Tx), which is optically excited by optical short pulses. The optical pulse source is produced from a self-developed photonic mm-wave waveform generator (PMWG), which allows spectral line-by-line pulse shaping. Hence these optical pulses have high tolerance to fiber chromatic dispersion. The W-band 10 Gb/s wireless data is transmitted and received via a pair of horn antennas. The received 10 Gb/s data is envelope-detected and then used to drive an optical modulator at the remote antenna unit (RAU) to produce the upstream signal sending back to the central office (CO). 20 km single mode fiber (SMF) error free transmission is achieved. Analysis about the optimum repetition rate of the optical pulse source and the transmission performance of the upstream signal are also performed and discussed. (C) 2012 Elsevier B.V. All rights reserved.
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
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
Extended-reach access network with downstream radio-over-fiber (ROF) signal and upstream NRZ signal using orthogonal-WDM
(2012-07-16)
Chow, C. W.
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Huang, S. P.
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Yang, L. G.
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Yeh, C. H.
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光電工程學系
We propose and demonstrate an extended-reach radio-over-fiber (ROF) access network. The double-sideband carrier-suppressed (DSCS) optical signal carries the downstream ROF signal. A continuous wave (CW) optical carrier is embedded into the DSCS optical signal and transmitted to the colorless optical networking unit (ONU)/remote antenna unit (RAU) for the upstream signal generation. At the ONU/RAU, the upstream data is orthogonally wavelength division multiplexed (WDM) onto this CW carrier; hence mitigating the cross-talk generated by the downstream signal. Analyses about the optimum power difference between the downstream and the CW signals; as well as the split-ratio are also preformed. (C) 2012 Optical Society of America
Self-starting S-band mode-locked fiber ring laser by polarization additive pulse mode-locking
(2013-01-01)
Yang, L. G.
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Jyu, S. -S.
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Yeh, C. H.
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Lin, S. B.
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Chow, C. W.
We have experimentally demonstrated a self-starting mode-locked fiber laser source operating at 1503 nm with 9 nm output bandwidth. The mode-locked laser works stably with a pumping threshold of 225 mW at 980 nm.
Stable and wavelength-tunable silicon-micro-ring-resonator based erbium-doped fiber laser
(2013-02-11)
Yang, L. G.
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Yeh, C. H.
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Wong, C. Y.
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Chow, C. W.
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Tseng, F. G.
In this work, we propose and demonstrate a stable and wavelength-tunable erbium-doped fiber (EDF) ring laser. Here, a silicon-on-insulator (SOI)-based silicon-micro-ring-resonator (SMRR) is used as the wavelength selective element inside the fiber ring cavity. A uniform period grating coupler (GC) is used to couple between the SMRR and single mode fiber (SMF) and serves also as a polarization dependent element in the cavity. The output lasing wavelength of the proposed fiber laser can be tuned at a tuning step of 2 nm (defined by the free spectral range (FSR) of the SMRR) in a bandwidth of 35.2 nm (1532.00 to 1567.20 nm), which is defined by the gain of the EDF. The optical-signal-to-noise-ratio (OSNR) of each lasing wavelength is larger than 42.0 dB. In addition, the output stabilities of power and wavelength are also discussed. (C) 2013 Optical Society of America
Wavelength-tunable Erbium-doped fiber laser using silicon-on-insulator (SOI) based micro-ring with narrow laser linewidth
(2015-01-01)
Yang, L. G.
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Chow, C. W.
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Yeh, C. H.
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Tsang, H. K.
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光電工程學系
We propose and demonstrate a wavelength-tunable and narrow-linewidth erbium-doped fiber (EDF) laser using silicon-on-insulator (SOI) based micro-ring. We discuss the wavelength selection and wavelength-tunable operation of the proposed fiber laser. The SOI based micro-ring is fabricated on a SOI wafer with a 0.22 um thick top silicon layer and a 2 um thick burial oxide (BOX) layer. In order to enhance the coupling efficiency between the SOI based micro-ring and the EDF, a pair of uniform period grating couplers are used. In the experiment, the lasing wavelengths can be tuned in the wavelengths range from 1532 nm to 1567.2 nm with a tuning step of 2 nm. The wavelength range and the tuning step are determined by the EDFA gain-bandwidth and the FSR of the SOI based micro-ring respectively. The OSNR of each lasing wavelength is > 42 dB. By using a double-ring configuration, a narrow laser linewidth of 50 kHz can be achieved.