Browsing by Author "Sien, Chi"

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Double-pass high-gain low-noise EDFA over Sand C+L-bands by tunable fundamental-mode leakage loss
(2007-02-19)
Hung, Chi-Ming
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Chen, Nan-Kuang
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Lai, Yinchieh
;
Sien, Chi
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光電工程學系
We demonstrate a high-gain low-noise double-pass tunable EDFA over S- and C+L-bands by discretely introducing fundamental-mode leakage loss in a 16-m-long standard C-band Er3+-doped fiber. The amplified spontaneous emission at the wavelengths of longer than 1530 nm can be substantially attenuated by the ASE suppressing filters to maintain high population inversion and to squeeze out the optical gain for S- band signals. When the filters are disabled, the gain bandwidth immediately returns back to the C+L-bands. Under S-band operation, a 37 dB small signal gain and a minimum 4.84 dB noise figure at 1486.9 nm are achieved with a 980 nm pump power of 154 mW. (c) 2007 Optical Society of America.
Evanescent-field optical amplifiers and lasers
(2004-11-04)
Nan-Kuang, Chen
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Sien, Chi
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Shiao-Min, Tseng
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Yinchieh, Lai
An optical amplifier and a laser generator based on the fiber side-polished technology having a high pumping efficiency, a low noise figure and a small footprint are provided in this application. The optical amplifier and the laser, which have a very long effective interaction length in conjunction with highly doped Erbium glass attached to its surface and an addition of a slanted fiber grating inscribed in the guiding core at the polished region can spatially separate the signal and pump power to simultaneously improve the pumping efficiency and optimize the penetrated depth of the signal evanescent-field. The spontaneous emission is kept from being amplified and therefore a high quality amplified signal is produced.
Fiber-optic tunable filter and intensity modulater
(2004-10-21)
Nan-Kuang, Chen
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Sien, Chi
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Shiao-Min, Tseng
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Fu-Yu, Tsai
A fiber-optic tunable filter and an intensity modulator respectively includes: a fiber having a polished surface and an evanescent-field; and a photonic crystal having plural cavities and a filler filled therein and attached to the polished surface, wherein the plural cavities and the filler decide a photonic band-gap of the photonic crystal and the photonic band-gap is adjusted to reflect a light with a specific wavelength through the evanescent interaction with the photonic crystal material. Based on the fiber side-polishing technique, all kinds of fiber active and passive devices are able to be manufactured easily, especially for a high speed intensity modulator using an EO (Electro-Optic) polymer as the filler.
Manufacturing method and apparatus of fiber coupler
(2004-06-24)
Sien, Chi
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Shiao-Min, Tseng
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Nan-Kuang, Chen
A manufacturing apparatus and method of a fiber coupler is provided. A movable electric arc is employed to fuse more than two stacked fibers for manufacturing a fiber coupler having a small size and good environment stability. It is advantageous that the fiber coupler can be used in a SDH (Synchronous Digital Hierarchy) communication system, and the method also be used to manufacture the all-fiber CWDM (Coarse Wavelength Division Multiplexing) multiplexer which covers the E-band wavelengths and the sub-components of the OADM (Optical Add/Drop Multiplexer). And, all these functions are difficult to be achieved by the conventional techniques.
Using intensity and wavelength division multiplexing for fiber Bragg grating sensor system
(2004-10-28)
Sien, Chi
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Hong-Yih, Tseng
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Peng-Chun, Peng
;
Jia-He, Lin
The present invention provides a fiber Bragg grating sensor system, which comprises a light-division device having receiving-sending terminals and sensing terminals, a light generating device and a photo detector coupled with receiving-sending terminal of a light-division device, sensing fibers coupled with the sensing terminals, said sensing fiber comprising a fiber Bragg grating, a information processor connecting with said photo detector. The light-division device distribute different optical energy ratio from said receiving-sending terminals to said sensing terminals. The intensity and wavelength division multiplexing can make different intensity for the information addressed of different sensing fiber on the same optical channel to enhance the sensing capacity of fiber Bragg grating sensor system.