Browsing by Author "Chien, HC"

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A novel scheme for better performance in optical code-division multiple access
(2005)
Peng, WR
;
Lin, WP
;
Chien, HC
;
Chi, S
;
交大名義發表
A new spectra-interleaved scheme for passive optical fast frequency-hopped code-division multiple access system is proposed. Interference and bit error rate are improved by numerical result with this new scheme.
A novel supervisory scheme for OXC based on different time-dilay recognition
(2005-12-01)
Lee, CC
;
Kao, TC
;
Chien, HC
;
Chi, S
;
光電工程學系
A novel supervising technique, based on different time-delay recognition scheme, for monitoring the switch fabric of optical cross-connects is proposed. This method features fast detection, high reliability, fault location, and actual routing information. The supervising of 4 x 4 switch fabric with a detecting time of less than 300 ns was achieved. It is also verified experimentally that the degradation of the system performance caused by this supervising approach is negligible.
A tunable and single-frequency S-band erbium fiber laser with saturable-absorber-based autotracking filter
(2005-06-01)
Chien, HC
;
Yeh, CH
;
Lee, CC
;
Chi, S
;
光電工程學系
A method to achieve wavelength tunability and single-longitudinal-mode oscillation in an S-band erbium-doped fiber (EDF) ring laser is proposed and demonstrated. A saturable-absorber-based autotracking filter consisting of an unpumped EDF and an optical reflector is utilized to provide fine mode restriction and guarantee the single-frequency operation. The performance of output power of larger than 1 dBm, power stability of smaller than 0.02 dB, wavelength variation of less than 0.01 nm and side-mode suppression ratio of larger than 31 dB has been experimentally demonstrated for this single-frequency fiber laser operating from 1482 to 1512 nm. (C) 2005 Elsevier B.V. All rights reserved.
All-optical 2R regeneration based on a compact self-seeded Fabry-Perot laser diode with an embedded fiber Bragg grating
(2006-01-01)
Chien, HC
;
Lee, CC
;
Chen, YM
;
Feng, KM
;
Chi, S
A cost-effective method, based on the injection-locking technique of a compact self-seeded Fabry-Perot laser diode with a 10-mm-long embedded fiber Bragg grating cavity, is proposed and experimentally compared with the two-mode injection-locked scheme for all-optical 2R regeneration at 10 Gb/s. Placing the presented all-optical 2R regenerator after a 50-km fiber significantly improves the transmission performance of a signal over 50- and 100-km fiber links. The power penalties at BER = 10(-9) are similar to those of the two-mode injection-locked scheme.
An all-optical 2R regenerator using a compact self-seeded Fabry-Perot laser diode incorporated in a bidirectional EDFA
(2006-05-01)
Chien, HC
;
Lee, CC
;
Chi, S
;
光電工程學系
;
Department of Photonics
An all-optical 2R regenerator, based on a compact self-seeded Fabry-Perot laser diode with a 10-mm-long embedded fiber Bragg grating cavity, and a bidirectional erbium-doped fiber amplifier, is proposed and experimentally demonstrated to execute all-optical 211 regeneration at 10 Gb/s. Compared with the conventional 111 regeneration, the proposed scheme has achieved significant 6.4-dB improvement of power penalty at bit-error ratio = 10(-9) in the transmission experiment over 100-km standard single-mode fiber.
An automatic gearshift logic for discrete bicycle transmissions
(2003)
Chien, HC
;
Tseng, CH
;
機械工程學系
;
Department of Mechanical Engineering
Considering the characteristics of a discrete transmission on bicycles, this study proposes an automatic gearshift logic for discrete bicycle transmissions. This logic calculates shifting occasions of a transmission for the individual. Shifting gears at these shifting occasions can keep the individual pedaling in the suitable cadence region, namely satisfy his/her ergonomic necessity.
An automatic transmission for bicycles: a simulation
(2004-02-01)
Chien, HC
;
Tseng, CH
;
機械工程學系
;
Department of Mechanical Engineering
A new design of an automatic transmission for bicycles was simulated. A sensitivity analysis found most environmental and bicycle variables had little effect but cycling velocity was very important while pedal rpm and gradient of the ground had some effect. The new design transmission therefore emphasizes velocity, pedal rpm and gradient of the ground when selecting the optimum gear ratios. Since the comfortable pedal rpm differs from cyclist to cyclist, this new automatic transmission continuously measures the pedal rpm and calculates an average to efficiently learn the cycling habit of different cyclists.
An effective statistical approach for comparative risk assessment
(1996-06-01)
Ding, CG
;
Woo, YY
;
Sheu, HJ
;
Chien, HC
;
Shen, SF
Comparative risk assessment is an evaluation process designed to rank environmental problems based on the severity of potential hazards. The purpose of this paper is to provide an effective statistical approach to analyze perceived environmental risks. Environmental problems, evaluative criteria, and other potential moderator variables need to be determined first, and then the risk perception data collected. Repeated measures analysis is used to first test for interactions between environmental problems and potential moderator variables. If there are no significant interactions, then the risk difference among environmental problems is tested unconditionally; otherwise the risk difference is tested conditionally. Cluster analysis for environmental problems is performed only when the risk difference is significant. The clustering results can be objectively determined by using the simultaneous T-confidence intervals. Risk-based priority setting is made according to the clusters obtained. To illustrate this approach, an empirical study of comparative socioeconomic risks in Taiwan was conducted. Socioeconomic impacts areas including social security, quality of life, production cost, investment willingness, and economic resources are used as evaluative criteria. Results indicate that selected impact areas do affect relative risk differences among 24 environmental problems, and the difference is significant for each area. Therefore, cluster analysis is conducted separately for each impact area. Risk-based priority settings for clusters of environmental problems are reported.
EDFA-free all-optical 2R regeneration using a compact self-seeded Fabry-Perot laser diode
(2006-05-01)
Chien, HC
;
Lee, CC
;
Chi, S
;
光電工程學系
;
Department of Photonics
This study presents an erbium-doped fiber amplifier (EDFA)-free all-optical 2R (reamplification and reshaping) regeneration scheme based on a compact self-seeded Fabry-Perot laser diode. The proposed 2R regenerator achieves a straight line transmission at 10 Gb/s over 76 Ion without either the EDFA or the external probe laser, both of which are traditionally required. Additionally, device characteristics such as data-rate transparency, input dynamic range, amplified gain, and 2R regeneration performance are investigated experimentally.
Gain-clamping erbium-doped waveguide amplifier module using optical feedback technique
(2005-02-01)
Yeh, CH
;
Chien, HC
;
Lee, CC
;
Chi, S
;
光電工程學系
A forward optical feedback technique for gain-clamping erbium-doped waveguide amplifier has been proposed and experimentally investigated. Three different saturated tones are selected in this proposed structure over the operation range from 1530 to 1550 nm to realize the amplification behaviors. Therefore, a dynamic range of input signal power from -9 to -40 dBm at 1552 nm is obtained when different power level and lasing position of the saturated tone are applied. In addition, the gain clamping performance has also been investigated experimentally under different operation conditions such as the lasing wavelength, the cavity loss and the input signal wavelength. (C) 2004 Elsevier B.V. All rights reserved.
Multiwavelength fiber laser using S-band erbium-doped fiber amplifier and semiconductor optical amplifier
(2006-03-01)
Peng, PC
;
Feng, KM
;
Chang, CC
;
Chiou, HY
;
Chen, JH
A multiwavelength fiber ring laser that is based on an S-band erbium-doped fiber amplifier (EDFA) and a semiconductor optical amplifier (SOA) is developed. An optical switch is used to switch the multiwavelength fiber laser between S-band and L-band. This fiber laser can stably lase seven wavelengths in the S-band or 28 wavelengths in the L-band. Additionally, the lasing wavelengths with a signal-to-noise ratio of over 33 dB and a wavelength spacing of 100 GHz are demonstrated experimentally. The average powers of the lasing wavelength in the S-band and the L-band are -7.53 and -12.15 dBm, respectively. (c) 2005 Elsevier B.V. All rights reserved.
Single-frequency tunable fiber ring laser based on erbium-doped waveguide amplifier and double filters
(2005-01-01)
Chien, HC
;
Yeh, CH
;
Lee, CC
;
Chi, S
;
光電工程學系
We have proposed and experimentally demonstrated a single-longitudinal-mode tunable fiber ring laser based on an erbium-doped waveguide amplifier (EDWA) and two filters composed of a Fabry-Perot laser diode and a fiber Fabry-Perot filter. The side-mode suppression ratio (SMSR) of > 32.6 dB/0.05 nm and the output power of > 1.4 dBm over a wide tuning range from 1525.22 to. 1565.45 nm in steps of 1.11 nm have been achieved for this ring laser. The power fluctuation of < 0.1 dB and central wavelength variation of < 0.01 nm also can be obtained.
Stable and tunable fiber double-ring laser based on an erbium-doped waveguide amplifier
(2005-04-01)
Chien, HC
;
Yeh, CH
;
Lee, CC
;
光電工程學系
;
Department of Photonics
A stable and tunable fiber double-ring laser based on an erbium-doped waveguide amplifier (EDWA) is proposed and experimentally demonstrated. A widely tunable range from 1527 to 1567 nm, the side-mode suppression ratio (SMSR) of > 45.6 dB/0.05 nm and the output power of > 1.04 dBm in the operating range from 1535 to 1565 nm can be achieved for this ring laser. By applying the double-ring configuration, the ring laser is stabilized. The central wavelength variation of < 0.02 nm and the power fluctuation of < 0.03 dBm can therefore be retrieved. (c) 2005 Society of Photo-Optical Instrumentation Engineers.
Stable and wavelength-tunable erbium-doped fiber double-ring laser in S-band window operation
(2005-05-01)
Chien, HC
;
Yeh, CH
;
Lai, KH
;
Lee, CC
;
Chi, S
A stable and tunable S-band erbium-doped fiber (EDF) double-ring laser has been proposed and experimentally demonstrated. Based on the double-ring configuration, the EDF ring laser exhibits more stable output wavelengths and powers than those of the single-ring. Wide tunable range of 1484-1518 nm, the side-mode suppression ratio (SMSR) of larger than 44.7 dB/0.05 nm and the output power of larger than -2.2 dB in over the operation range of 1484-15 10 nm have been retrieved. (c) 2005 Elsevier B.V. All rights reserved.
Using optical Fabry-Perot devices for a wavelength-tunable S-band erbium-doped fiber ring laser with single-frequency operation
(2005-10-01)
Yeh, CH
;
Chien, HC
;
Cheng, BC
;
Lee, CC
;
Chi, S
We have proposed and experimentally demonstrated a stabilized and tunable S-band erbium-doped fiber ring laser by using a Fabry-Perot laser diode (FPLD) and a fiber Fabry-Perot filter inside the ring cavity. Due to the bandwidth limitation of the FPLD, the effective operating range of the proposed laser is confined to 1490.28 to 1521.22 nm with a tuning step of 0.08 nm. A side-mode suppression ratio of > 39.1 dB at 0.05 nm and an output power of > 0.4 dBm can be achieved while this laser is tuned from 1490.28 to 1510.27 nm. Zero output wavelength variation and output power fluctuation <= 0.03 dB have also been obtained. (c) 2005 Society of Photo-Optical Instrumentation Engineers.