Browsing by Author "Lai Yin-Chieh"

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Displacement measurement system and method thereof
(2012-01-03)
Hsu Kuei-Chu
;
Chen Chii-Chang
;
Chan Chia-Hua
;
Lai Yin-Chieh
A displacement measurement system including a coherent light source, a two-dimensional grating, a photo sensor, and a signal processing apparatus is provided. After the coherent light beam enters the two-dimensional grating, a zero-order light beam and a plurality of first-order diffraction beams are generated. The zero-order light beam interferes with two of the first-order beams in different directions, so that corresponding interference fringes are formed on the photo sensor. Accordingly, when the two-dimensional grating moves, displacements of the two-dimensional grating in the different directions are obtained by calculating phase differences of the interference fringes in the corresponding directions. Besides, when the two-dimensional grating rotates, the rotational angle of the two-dimensional grating is obtained from the corresponding rotational angle of a diffraction pattern of the first-order diffraction beams.
Long-length fiber Bragg creating sequential UV writing by probing phase mask
(2011-09-27)
Hsu Kuei-Chu
;
Lai Yin-Chieh
;
Hsin Chen-Wei
A new fiber position monitoring method for sequential FBG UV-writing processes with a reference phase mask as the phase reference is proposed. Also, the new method by probing a reference phase mask can overcome the optical alignment difficulties in using reference fiber as well as provide more signal power for achieving better monitoring accuracy. Moreover, the present invention provides a method for sequentially joining a plurality of grating sections into a fiber grating longer than a phase mask.
System and method for measuring dispersion
(2012-01-24)
Jyu Siao-Shan
;
Lai Yin-Chieh
;
Liu Shiou-Fong
;
Hsiang Wei-Wei
;
Chang Hon-Chieh
A method for measuring dispersion in an optical fiber is provided and includes the following steps. A periodic wavelength variation pulse light signal is generated by a periodic frequency-swept pulse light source, in which the periodic wavelength variation pulse light signal has periodic wavelength variations. The periodic wavelength variation pulse light signal is transmitted into a test optical fiber. The periodic wavelength variation pulse light signal propagating through the test optical fiber is detected to generate a sensing signal. The sensing signal is transformed into an RF spectrum to obtain a slow periodic pulse timing variation of the periodic wavelength variation pulse light signal in accordance with the RF spectrum. A dispersion value of the test optical fiber is obtained in accordance with the slow periodic pulse timing variation. A system for measuring dispersion in a fiber is also disclosed herein.