Browsing by Author "CHI, S"

Now showing 1 - 20 of 46

APPROXIMATE SOLUTION OF OPTICAL SOLITON IN LOSSLESS FIBERS WITH 3RD-ORDER DISPERSION
(1989-07-01)
WEN, SF
;
CHI, S
;
交大名義發表
;
光電工程學系
;
National Chiao Tung University
ATTENUATION AND FLUORESCENCE CHARACTERISTICS OF OPTICAL SIGNALS PROPAGATING IN AN ERBIUM-DOPED FIBER
(1993-09-01)
CHEN, CY
;
CHI, S
;
光電工程學系
;
Department of Photonics
For a monochromatic input signal launched into an erbium-doped fiber (EDF), a broadband fluorescence spectrum will be generated with total power approximately 30 dB lower than input signal power. The forward fluorescence power decays slowly at long EDF length due to smaller absorption cross section for wavelength components away from absorption peal Care must be taken when the conventional cutback method is used to measure the attenuation of the optical signals in an EDF. The backward fluorescence power is saturated to a constant level, and the spectrum does not change for long EDF.
BEAM PROPAGATION METHOD ANALYSIS OF TRANSVERSE-ELECTRIC WAVES PROPAGATING IN A NONLINEAR TAPERED PLANAR WAVE-GUIDE
(1991-11-01)
SHI, TT
;
CHI, S
;
光電工程學系
;
電信研究中心
;
Department of Photonics
The propagation of TE-polarized guided waves in a nonlinear tapered waveguide is studied. The incident fields are chosen from the stable branches of the nonlinear dispersion curve in its uniform section. The propagations of the field in both directions are calculated by the beam-propagation method. Wave propagation in the tapered waveguide is discussed in terms of the nonlinear dispersion curves of the waveguide. Depending on the intensity, the field can radiate as a spatial soliton or it can have an abrupt transition between the guided mode and the surface polariton. The wave propagation of an incident field that is composed of a dominant TE0 wave and a small TE1 wave is investigated. Finally, using a property of this wave propagation, we present a new device for continuous signal routing.
BIDIRECTIONAL OPTICAL FIBER TRANSMISSION-SYSTEMS USING RAMAN AMPLIFICATION
(1988-02-01)
CHI, S
;
KAO, MS
;
光電工程學系
;
Department of Photonics
CHARACTERISTICS OF THE GAIN AND SIGNAL-TO-NOISE RATIO OF A DISTRIBUTED ERBIUM-DOPED FIBER AMPLIFIER
(1992-12-01)
WEN, SF
;
CHI, S
;
光電工程學系
;
Department of Photonics
The effects of the stimulated Ramam scattering (SRS) on the gain and signal-to-noise ratio (SNR) of the DEDFA with 100-km fiber length and with bidirectional pumps are numerically studied. It is found that the gain and SNR are significantly enhanced by the SRS with practical parameters. For 1.55-mum signal and 10-muW initial signal power, there are 8.8-dB gain enhancement and 3.3-dB SNR enhancement for 1.48-mum pump wavelength and 75-mW initial pump power. The characteristics of the gain and SNR enhancements due to SRS are studied for different signal wavelength, signal powers, pump wavelengths, pump powers, and effective fiber cross sections. The results show that the gain and SNR are decreased by SRS only for the unpractical high pump power and/or small effective fiber cross section.
CONCATENATED SOLITON FIBER LINK
(1991-01-31)
CHI, S
;
LIN, MC
;
光電工程學系
;
電信研究中心
;
Department of Photonics
An easy and practical 'soliton fibre' link by concatenating uniform fibre sections is proposed. An ultrahigh bit rate loss-limited fibre communication system can be achieved.
DEMONSTRATION OF IN-SERVICE SUPERVISORY REPEATERLESS BIDIRECTIONAL WAVELENGTH-DIVISION-MULTIPLEXING TRANSMISSION-SYSTEM
(1995-09-01)
CHEN, YK
;
GUO, WY
;
CHI, S
;
WAY, WI
;
電信研究中心
An in-service supervisory repeaterless bidirectional wavelength-division-multiplexing (WDM) transmission system using optical fiber amplifiers is demonstrated for the first time. The system supervision by an optical time domain reflectometer (OTDR) is achieved without degrading the 2.5 Gb/s service over a bidirectional six-WDM-channel 200-km single-fiber link, Negligible system penalties of dispersion and counter-directional transmission crosstalk are observed.
DISTRIBUTED ERBIUM-DOPED FIBER AMPLIFIERS WITH STIMULATED RAMAN-SCATTERING
(1992-02-01)
WEN, S
;
CHI, S
;
光電工程學系
;
電信研究中心
;
Department of Photonics
The effect of stimulated Raman scattering (SRS) on the distributed erbium-doped fiber amplifier with 1.48-mu-m pump wavelength and 1.55-mu-m signal wavelength is numerically studied. The contributions of the gains from SRS and the pumped erbium ions doped in the fiber core are shown. It is found that SRS enhances both the gain and signal-to-noise ratio of the amplifier except the signal-to-noise ratio may be decreased by SRS for high initial signal power.
EFFECT OF CARRIER DEPLETION ON OPTICAL-PHASE CONJUGATION IN A SEMICONDUCTOR-LASER AMPLIFIER
(1995-03-15)
WEN, S
;
CHI, S
;
光電工程學系
;
Department of Photonics
The temporal effect of optical phase conjugation in a semiconductor laser amplifier is studied numerically. The conjugate pulse has distortion and frequency chirping owing to the carrier depletion induced by the signal pulse. Both the pulse-shape distortion and frequency chirping are enhanced as the signal power and the injection current increase. We can reduce these two effects by increasing the pump power to reduce the carrier-density depletion induced by the signal pulse.
EFFECT OF CROSS-PHASE MODULATION ON OPTICAL-PHASE CONJUGATION IN DISPERSION-SHIFTED FIBER
(1994-07-01)
WEN, SF
;
CHI, S
;
CHANG, TC
;
光電工程學系
;
Department of Photonics
The temporal effect of optical phase conjugation in dispersion-shifted fiber is studied numerically. Frequency chirping is induced in the conjugate pulse by the signal pulse and the pump wave through cross-phase modulation, which increases with the signal power and may distort the pulse shape when the conjugate pulse propagates in the standard fiber. It is also shown that, when the signal power is low, the optical phase conjugation is nearly ideal.
EXTINCTION RATIO DEGRADATION IN RAMAN AMPLIFIED OPTICAL COMMUNICATION-SYSTEM
(1991-07-04)
KAO, MS
;
CHI, S
;
電信工程研究所
;
光電工程學系
;
電信研究中心
The extinction ratio of a Raman amplified optical fibre system is investigated. The results show that serious extinction ratio degradation occurs at high pump level. Because the Raman gain increases with pump power, there exists a trade-off between the extinction ratio and the achievable amplifier gain. A design rule to estimate the suitable pump power is presented.
FEMTOSECOND SOLITON PROPAGATION IN ERBIUM-DOPED FIBER AMPLIFIERS - THE EQUIVALENCE OF 2 DIFFERENT MODELS
(1994-03-15)
CHI, S
;
CHANG, CW
;
WEN, S
;
光電工程學系
;
Department of Photonics
The femtosecond soliton propagation in erbium-doped fiber amplifiers (EDFA) was calculated by using the coupled Maxwell-Bloch equations and the modified nonlinear Schrodinger equation with a complex lorentzian pin profile, respectively. Two results are found to be almost identical for the practical parameters of the EDFA. Therefore, accurate results can be obtained using the complex lorentzian gain profile, and it is much more time saving.
HYBRID TRANSMISSIVE OPTICAL STAR COUPLERS WITH GAIN USING FIBER AMPLIFIERS
(1993-02-01)
CHEN, YK
;
CHI, S
;
LIAW, JW
;
光電工程學系
;
電信研究中心
A hybrid transmissive star coupler incorporating fiber amplifiers for WDM/FDM networks is proposed. It is found that the total fiber length and conduit length required for this hybrid star coupler/network can be reduced tremendously as comparing with either the centralized or the distributed cases. Furthermore, this coupler is easier to construct and more cost-effective.
IMPROVING SOLITON TRANSMISSION BY OPTICAL-PHASE CONJUGATION
(1994)
CHI, S
;
WEN, S
;
光電工程學系
;
Department of Photonics
IMPROVING THE UNDOING OF SOLITON INTERACTION WITH OPTICAL-PHASE CONJUGATION BY PHASE ALTERNATION BETWEEN NEIGHBORING SOLITONS
(1995-05-15)
CHI, S
;
DUNG, JC
;
WEN, SF
;
光電工程學系
;
電信研究中心
The undoing of the soliton interaction with the optical phase conjugation by the phase alternation between neighboring solitons is numerically studied. When the phase alternation is larger than 90-degrees, the undoing of the soliton interaction is good even when the conjugation is applied at the distance where the solitons interact seriously.
IN-SERVICE SUPERVISORY EDFA-REPEATED WAVELENGTH-DIVISION MULTIPLEXING TRANSMISSION-SYSTEM
(1995-08-01)
CHEN, YK
;
GUO, WY
;
WAY, WI
;
CHI, S
;
光電工程學系
An in-service supervisory wavelength division multiplexing (WDM) transmission system is demonstrated for the first time. Simultaneous fault location and EDFA status-monitoring are achieved without degrading the 2.5 Gb/s service in a five-EDFA, 365-km, four-WDM-channel system.
INTERACTION OF OPTICAL SOLITONS WITH A FORWARD RAMAN PUMP WAVE
(1989-01-01)
CHI, S
;
WEN, S
;
交大名義發表
;
光電工程學系
;
National Chiao Tung University
MAXIMUM BITRATE-LENGTH PRODUCT IN THE HIGH-DENSITY WDM OPTICAL FIBER COMMUNICATION-SYSTEM
(1990-08-30)
CHI, S
;
WANG, SC
;
光電工程學系
;
電信研究中心
;
Department of Photonics
MEASURING EMISSION CROSS-SECTION PROFILE OF ERBIUM-DOPED FIBER WITH LOW-INPUT POWER
(1994-05-26)
CHEN, CY
;
WEN, S
;
CHI, S
;
光電工程學系
;
電信研究中心
A simple and elegant method is proposed to measure the emission cross-section profile of erbium-doped fibre by using a short piece of erbium-doped fibre with input pump or signal power less than 1mW. Relative error is within 1% over the whole spectrum. The theoretical and experimental results are discussed.
NONLINEAR PHOTONIC SWITCHING BY USING THE SPATIAL SOLITON COLLISION
(1990-10-15)
SHI, TT
;
CHI, S
;
交大名義發表
;
光電工程學系
;
National Chiao Tung University