Browsing by Author "Chiou, A"

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One-dimensional self-focusing in photorefractive Bi12SiO20 crystal: theoretical modeling and experimental demonstration
(1999-04-15)
Tsai, J
;
Chiou, A
;
Hsieh, TC
;
Hsu, K
;
電子物理學系
We have experimentally demonstrated one-dimensional self-focusing of a laser beam in a photorefractive Bi12SiO20 (BSO) crystal with an externally applied DC field. Fractional change in focal length larger than 50% was measured when the biased field was varied from 2 kV/cm to 8 kV/cm. Based on the band transport model, thin crystal approximation, and gradient index (GRIN) lens approximation, we derive a mathematical expression that describes the effect quantitatively. (C) 1999 Elsevier Science B.V. All rights reserved.
Optimal conditions for thermal fixing of volume holograms in Fe : LiNbO3 crystals
(1999-10-10)
Hsieh, CR
;
Lin, SH
;
Hsu, KY
;
Hsieh, TC
;
Chiou, A
We analyze and compare two typical recording and thermal fixing procedures of a volume hologram in a Fe:LiNbO3 crystal (low-high-low procedure and high-low procedure). We consider the kinetics of the recording, compensating, and developing processes by taking into account the ratio of the conductivities between the protons and the electrons as a function of temperature. From the analysis the optimal environmental conditions tin terms of the fixing temperature and the compensation time) for each fixing procedure can be deduced for a crystal with given material parameters. (C) 1999 Optical Society of America.
The self-defocusing of a diffraction beam in a photorefractive crystal and its application in a Fourier plane multiple beam splitter
(1999-09-15)
Tsai, J
;
Chiou, A
;
Hsieh, TC
;
Hsu, K
;
電子物理學系
We propose using a diffraction beam to induce a self-defocusing lens and applying it in a Fourier plane multiple beam splitter (FPMBS). The self-induced lens array in the FPMBS can increase the splitting ratio, which is generated by inserting a photorefractive crystal at the Rayleigh distance of the diffraction beam from each pixel. (C) 1999 Elsevier Science B.V. All rights reserved.