Browsing by Author "Chu, SC"

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A tabu search based maximum descent algorithm for VQ codebook design
(2001-09-01)
Huang, HC
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Chu, SC
;
Pan, JS
;
Lu, ZM
;
電子工程學系及電子研究所
A maximum descent (MD) method has been proposed for vector quantization (VQ) codebook design. Compared with the traditional generalized Lloyd algorithm (GLA), the MD algorithm achieves better codebook performance with far less computation time. However, searching for the optimal partitioning hyperplane of a multidimensional cluster is a difficult problem in the MD algorithm. Three partition techniques have been proposed for the MD method in the literature. In this paper, a new partition technique based on the tabu search (TS) approach is presented for the MD algorithm. Experimental results show that the tabu search based MD algorithm can produce a better codebook than can the conventional MD algorithms.
Characterization of the signature of subwavelength variation from far-field irradiance
(2004-05-15)
Chu, SC
;
Chern, JL
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光電工程學系
;
Department of Photonics
The dynamic signature of the subwavelength variation of a slit is shown to be determinable from far-field irradiance with a precision of better than 1 nm. One can increase the efficiency of measurement of the subwavelength's signature by adjusting the detection width over which the subwavelength variation is detected. The subwavelength variation of a rectangular aperture was also examined to show the general feasibility. (C) 2004 Optical Society of America
Detection of subwavelength slit-width variation with measurements in the far field by use of an embedded-aperture interferometer configuration
(2005-02-01)
Chu, SC
;
Chern, JL
;
友訊交大聯合研發中心
;
D Link NCTU Joint Res Ctr
The dynamic signature of the subwavelength variation of a rectangular aperture has recently been Shown to be determinable from far-field irradiance with a precision better than 1 nm [Opt. Lett. 29, 1045 (2004)]. We have proposed, and have theoretically shown, that detection sensitivity can be greatly enhanced with an embedded-aperture Mach-Zehnder interferometer configuration, after parameter optimization. The sensitivity, in terms of derivative intensity of observed subwavelength variations, could be enhanced approximately 2.7 times, compared with the directly detected method. Another method of detection of subwavelength variation from pattern measurement of far-field diffraction has also been proposed. The associated shifting of the dark line of the diffraction pattern had a good linear correlation to subwavelength variation, which was magnified approximately 150 times, and gave good contrast for measurement. (C) 2005 Optical Society of America.
Identifying the subwavelength-aperture-width variation in the far field with tunable asymmetrically-embedded-aperture interferometer configuration
(2005-08-01)
Chu, SC
;
Chern, JL
;
光電工程學系
;
Department of Photonics
A tunable asymmetrically-embedded-aperture interferometer configuration is proposed to enhance the measurement sensitivity of subwavelength variation. With this configuration, an aperture of reference was posited asymmetrically, relative to the test aperture, that exhibited subwavelength variation. By a shift in the relative position of the reference aperture, the detection sensitivity of measuring the subwavelength variation in the far field can be enhanced to a desired value at any specific detection width. We discuss the underlying mechanism of optimization and address the difference between the embedded-aperture interferometry and tunable asymmetrically-embedded-aperture interferometry with respect to tolerance. (C) 2005 Optical Society of America.
No-loss bent light pipe with an equiangular spiral
(2005-11-15)
Chu, SC
;
Chern, JL
;
光電工程學系
;
Department of Photonics
Bending a light pipe and maintaining the required volume and size, while at the same time preserving source energy and minimizing bend losses, is the basic criterion for designing a light pipe. An important requirement is the design of a light pipe that is capable of being bent without loss of light and with no limitations on acceptance angle. It is shown that in theory such a light pipe does exist, in a form corresponding to the so-called golden rectangle. Numerical simulations with six different no-loss light pipes with multiple bends are provided as a demonstration. (c) 2005 Optical Society of America
Suppression of boron penetration for p(+) stacked poly-Si gates by using inductively coupled N-2 plasma treatment
(1999-10-01)
Cheng, HC
;
Lai, WK
;
Hwang, CC
;
Juang, MH
;
Chu, SC
Nitridation of the stacked poly-Si gates by the inductively coupled N-2 plasma (ICNP) treatments has been shown to suppress the boron penetration and improve the gate oxide integrity. The ICNP treatments on the stacked poly-Si layers would create the nitrogen-rich layers not only between the stacked poly-Si layers but also in the gate oxide after post implant anneal, thus resulting in effective retardation of boron diffusion. In addition, the position of ICNP treatment closer to gate oxides leads to higher nitrogen peaks in the gate oxide region, resulting in further suppression of boron penetration and improvement of gate oxide reliability.