Browsing by Author "Lee, Chien-Chung"

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14 dB gain, 1.3 mu m diode laser amplifier with reshaping capability using main-mode suppression and injection technique
(2006)
Chien, Hung-Chang
;
Lee, Chien-Chung
;
Chi, Sien
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光電工程學系
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Department of Photonics
A novel and cost-effective 1.3 mu m diode laser amplifier with reshaping capability using main-mode suppression and injection technique is proposed. 14-dB gain and 10-Gb/s transmission over 60-km with power penalty < 0.84 dB are achieved.
All-optical 2R regenerator using self-seeded laser diode
(2007-11-29)
Chi, Sien
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Lee, Chien-Chung
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Chien, Hung-Chang
The present invention is a self-seeded laser diode. The laser diode obtains a gain by itself without using expansive erbium-doped fiber amplifiers. Hence, the cost is reduced and the system is simplified.
EDFA-free all-optical 2R regeneration using a compact self-seeded Fabry-Perot laser diode (vol 18, pg 1112, 2006)
(2006-09-01)
Chien, Hung-Chang
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Lee, Chien-Chung
;
Lin, Chun-Ting
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Chi, Sien
;
光電工程學系
Fast wavelength-tunable laser system using fabry-perot laser diode
(2005-08-18)
Chi, Sien
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Lee, Chien-Chung
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Yeh, Chien-Hung
The invention relates to a laser system using a multi-longitudinal-mode Fabry-Perot laser diode as an inter-injection light source and a gain cavity formed by other laser diodes of such type so as to achieve the function of fast wavelength switching, so that it is possible to achieve repetitively fast switching of wavelength by varying and controlling the bias voltage of maximum optical gain in said inter-injection type multi-longitudinal-mode Fabry-Perot laser diode so as to achieve three different wavelengths with tuning range of 3.5 nm for a side-mode suppression ratio (SMSR) greater than 19 dB and a response time of wavelength switching in the order of nanosecond.
Feasibility demonstration of 1.3/1.5 mu m amplifier-free transmission link at 10 Gb/s using two-mode injection locked laser diode as low-cost all-optical 2R regenerator
(2006)
Chien, Hung-Chang
;
Lee, Chien-Chung
;
Chi, Slen
;
光電工程學系
;
Department of Photonics
This study presents amplifier-free all-optical 2R regeneration schemes based on a compact self-seeded Fabry-Perot laser diode (SSFP-LD) at 1.5 mu m and a two-mode injection locked distributed feedback laser diode (TMIL DFB-LD) at 1.3 mu m, respectively. The proposed 2R regenerator achieve straight line transmissions at 10 Gb/s over 60/76 km at 13/1.5 mu m without any traditionally required optical amplifier. In addition, the amplified gain and regeneration performance is experimentally investigated.
Method of enhancing spatial resolution for distributed temperature measurement
(2003-06-05)
Chi, Sien
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Chiang, Po-Wen
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Lee, Chien-Chung
A method that utilizes a short sampling interval and a long-pulsewidth laser source to obtain the long sensing range and employs a signal processing technique of decomposing Brillouin spectrum to achieve high spatial resolution, high temperature resolution of the distributed temperature measurement is disclosed. The present method includes the steps of measuring the Brillouin spectra of an optical pulse applying to a sensing fiber and a overlapped area thereof, determining the length that the pulse enters according to the measured Brillouin spectra and a weighting factor and then determining a real Brillouin spectrum profile and a temperature distribution according to Brillouin frequency shifts thereof. For a 9500-m sensing range of standard single-mode fiber and a 100-ns pulsewidth laser source, spatial and positon resolutions of 20 cm and a temperature resolution of 1° C. are simultaneously achieved by using this signal processing method.
Method of utilizing a fiber for simultaneously measuring distributed strain and temperature
(2003-06-05)
Chi, Sien
;
Chiang, Po-Wen
;
Lee, Chien-Chung
A method that utilizes a dispersion-shifted fiber having compound compositions with different temperature coefficients in core to simultaneously measure the distributed strain and temperature based on Brillouin frequency shift is disclosed. The present method includes the steps of obtaining mean two peak frequencies in a multi-peak Brillouin spectrum of the dispersion-shifted fiber, determining a temperature change according to the formula of a Brillouin frequency shift of the peak relating to strain and temperature conditions of the fiber, and determining a strain change through the formula. In a 3682-m sensing length of Large-Effective-Area NZ-DS fiber, a temperature resolution of 5° C., a strain resolution of 60 με and a spatial resolution of 2 m are achieve simultaneously.
Optical monitoring apparatus for use in wavelength division multiplexing network
(2005-04-07)
Chi, Sien
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Lee, Chien-Chung
;
Yeh, Chien-Hung
An optical monitoring apparatus based on the scanning of the gain profile of erbium-doped fiber amplifiers (EDFA) and applied in a wavelength division multiplexing network has been proposed and experimentally demonstrated. The EDFA with an injected saturated tone can provide variable gain or loss profile by controlling the pump power. The components used in the present optical monitoring apparatus for use in a wavelength division multiplexing network are easily available and cost-effective, valuable for monitoring frequency and power of a WDM optical communication system, and capable of greatly enhancing resolution of monitoring frequency spectrum for the optical fiber network system.
Prenatal detection and characterization of a small supernumerary marker chromosome (sSMC) derived from chromosome 22 with apparently normal phenotype
(2006-10-01)
Lin, Chyi-Chyang
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Hsieh, Yao-Yuan
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Wang, Chung-Hsing
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Li, Yueh-Chun
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Hsieh, Lie-Jiau
Objective To present prenatal findings and molecular cytogenetic characterization of a small supernumerary marker chromosome (sSMC) derived from chromosome 22 with apparently normal phenotype. Case and Methods An amniocentesis was performed at 15 weeks' gestation and a small marker chromosome in the female fetus of a twin pregnancy was noted. A second amniocentesis was performed at 18 weeks; G-banding analysis on amniotic cells confirmed the small marker chromosome found in the female fetus. Both parents and the male twin fetus had normal karyotypes. Spectral karyotyping (SKY), Fluorescence in situ hybridization (FISH) analyses with chromosomal specific whole chromosome painting probe (WCP 22) and alphoid satellite DNA probe (D22Z4) Were used to identify the origin of the sSMC. The make-up of the sSMC was characterized by further FISH studies with chromosome region specific probes. The twin babies were delivered normally at 35 weeks' gestation. The female neonate with sSMC did not show any dysmorphic features, except for a type II atrial septum defect (ASD) at birth. She was found to be developing and growing normally at her 2-year follow-up. Results Conventional G-banding study confirmed the presence of a sSMC with bi-satellites. SKY and FISH with D22Z4 probes showed that the marker originated from chromosome 22. FISH studies using 4 locus-specific DNA probes in the 22q11.2 region (N25 probe to detect the D22S75 locus within the velocardiofacial syndrome/Di George syndrome (VCFS/DGS) critical region, a clone to detect the Bid locus just distal to the cat eye syndrome (CES) critical region and two clones 77H2 and 109L3 to detect the proximal end of the CES critical region, (CECR2 and CECR7), did not reveal any hybridization signal with the marker chromosome. The karyotype of the fetus was 47,XX,+mar. ish der(22) (SKY+,D22Z42+,CECR7-,CECR2-, BID-,D22S75-). Conclusion The supernumerary marker chromosome in this case was a de novo inv dup(22)(q11.2) and contained a duplicated proximal long arm region <400 kb from the centromere; it did not appear to affect the phenotype of the child. Copyright (C) 2006 John Wiley & Sons, Ltd.