Browsing by Author "Han, CY"

Now showing 1 - 4 of 4

Determination of optical parameters of a twisted-nematic liquid crystal by phase-sensitive optical heterodyne interferometric ellipsometry
(2005-12-10)
Tsai, CC
;
Chou, C
;
Han, CY
;
Hsieh, CH
;
Liao, KY
What is believed to be a novel phase-sensitive optical heterodyne interferometric ellipsometer is set up to characterize a twisted-nematic liquid crystal (TN-LC) by the elliptical parameters of the output polarization state. This ellipsometer presents the advantages of both polarized optical heterodyne interferometry and optical photometry, which introduce a polarization modulation that is capable of performing with high-sensitivity on phase detection in real time. The twist angle Phi and the untwisted phase retardation Gamma of TN-LC are measured precisely. The experimental results verify that a TN-LC can be treated as identical to an elliptical retarder. (c) 2005 Optical Society of America.
Photoelastic modulated imaging ellipsometry by stroboscopic illumination technique
(2006-02-01)
Han, CY
;
Chao, YF
;
光電工程學系
;
Department of Photonics
A novel stroboscopic illumination technique is applied in a photoelastic modulated (PEM) ellipsometry to conquer the slow imaging processing of charge-coupled device camera system and form a fast imaging ellipsometry. The synchronized ultrastable short pulse is used to freeze the intensity variation of the PEM modulated signal. The temporal phase is calibrated with respect to the time reference of PEM. The laser diode is modulated by a programable pulse generator for triggering four short pulses at their specific temporal phase angle. The two-dimensional (2D) ellipsometric parameters can be deduced from those recorded four images. Therefore, the 2D thickness profile of a patterned sample can be measured; a static patterned SiO2 thin film on silicon substrate and the drainage behavior of matching oil on silicon wafer were studied by this imaging ellipsometry. (c) 2006 American Institute of Physics.
Two-dimensional linear Birefringence vector measurement by polarization-stepping interferometer
(2004-04-01)
Lang, KC
;
Teng, HK
;
Chang, HF
;
Han, CY
;
Chou, C
A simple polarization-stepping technique in combination with a common-path homodyne interferometer is proposed in order to measure the phase retardation and the fast-axis angle, which are defined as the linear birefringence vector (LBV), of a wave plate (WP). At three different orientation angles of the linear polarization of incident laser beam, two-dimensional (2-D) interference patterns with respect to different orientation angle are recorded by using a CCD camera. Thus, 2-D phase retardation and fast-axis angle distributions of WP are determined simultaneously. In addition, the elliptical polarization and misalignment of the orientation angle of the incident laser beam induced errors on LBV measurement are discussed
Ultra-fast surface plasmon resonance biological detection by means of photoelastic modulated ellipsometry
(2004)
Han, CY
;
Chao, YF
;
Lee, CL
;
光電工程學系
;
Department of Photonics
A photoelastic modulated ellipsometry combined with SPR technique is proposed. In addition to monitor the biological interactions in real time, we also installed a post flight analysis technique to analyze the same system synchronously.