Browsing by Author "Chan, Chia-Hua"

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DISPLACEMENT MEASUREMENT SYSTEM AND METHOD THEREOF
(2010-11-11)
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.
Simultaneous two-dimensional nanometric-scale position monitoring by probing a two-dimensional photonic crystal plate
(2010-01-01)
Hsu, Kuei-Chu
;
Chen, Chii-Chang
;
Chan, Chia-Hua
;
Chung, Pei-Fang
;
Lai, Yinchieh
Simultaneous two-dimensional nanometric-scale position monitoring can be achieved in a simple interferometric setup by real-time probing a hexagonal photonic crystal glass substrate. The minimum detectable translational movement is determined by the period of photonic crystal array, and can be as high as 8 nm in the present work.