Browsing by Author "Chuang, WC"

Now showing 1 - 5 of 5

Analysis of a liquid crystal Fabry-Perot etalon filter: A novel model
(1997-04-01)
Chen, PL
;
Lin, KC
;
Chuang, WC
;
Tzeng, YC
;
Lee, KY
The authors propose a novel analysis method to investigate the characteristics of an electrically tunable liquid-crystal Fabry-Perot interferometer (LC-FPI), Based on the solution of deformation analysis of liquid crystal in an electric field and the assumption of small refractive index variation in the Fabry-Perot cavity, the voltage-dependent equivalent refractive index of the cavity has been derived. Tuning behaviors of the LC-FPI filter were simulated by means of the dependence, The calculated result and the experimental measured data agree well with each other.
Analysis of a liquid crystal Fabry-Perot etalon filter: A novel model
(1997-04-01)
Chen, PL
;
Lin, KC
;
Chuang, WC
;
Tzeng, YC
;
Lee, KY
The authors propose a novel analysis method to investigate the characteristics of an electrically tunable liquid-crystal Fabry-Perot interferometer (LC-FPI), Based on the solution of deformation analysis of liquid crystal in an electric field and the assumption of small refractive index variation in the Fabry-Perot cavity, the voltage-dependent equivalent refractive index of the cavity has been derived. Tuning behaviors of the LC-FPI filter were simulated by means of the dependence, The calculated result and the experimental measured data agree well with each other.
Comparative study of Schottky diode characteristics in Ni, Ta and Ni/Ta metal contact schemes on n-GaN
(2001-07-01)
Chen, GL
;
Chang, FC
;
Chuang, WC
;
Chung, HM
;
Shen, KC
We have reported current-voltage characteristics of Ta/- and Ni/Ta/n-GaN Schottky diodes under various thermal treatments. Experimental data indicate that the electrical characteristics of Ni/Ta diodes are controlled by the interfacial properties of the Ta and GaN heterointerface for the as-deposited samples and strongly affected by the presence of an oxide layer (Ta2O5) in those high-temperature-annealed diodes. In regard to Ta/Ni diodes, probably because of thermal stability and wide-bandgap properties of tantalum oxide, dramatic improvement in Schottky diode performance was resulted after annealing at high temperatures. The corresponding barrier height and ideality factor values can reach 1.17 cV and 1.09, respectively, even at an annealing temperature of 800 degreesC.
Long-term photocapacitance decay behavior in undoped GaN
(2001-10-01)
Chung, HM
;
Pan, YC
;
Chuang, WC
;
Chen, NC
;
Tsai, CC
We have measured the dynamic response of the photocapacitance of a Schottky diode made of an undoped GaN epilayer grown by metalorganic vapor phase epitaxy. The measurements were performed after the suspension of a white light for a specified "waiting" time, t. The results indicate that the capacitance exhibits a logarithmic function of t from which a time constant of approximately 34.5 s and a cross-sectional area of less than 2.89 x 10(-27) cm(2) were retrieved. These are interpreted as the characteristic time and the cross-sectional area of electron capture by the traps associated with dislocations formed in the epifilm, respectively.
Measurement of electrically tunable liquid-crystal Fabry-Perot interferometer using a monochromatic light source
(1999-07-05)
Lin, KC
;
Lin, JS
;
Chen, PL
;
Chuang, WC
;
光電工程學系
We propose a novel technique to characterize an electrically tunable liquid-crystal Fabry-Perot interferometer. Only one usual set of a monochromatic light source and an optical power meter is needed. Various characteristic parameters were estimated based on the equivalent refractive index analysis and the measured voltage-dependent transmittance. (C) 1999 John Wiley & Sons, Inc.