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In this study, an intensity-sensitive polarization modulation polarimeter (IPMP) was proposed and set up in order to measure the cell parameters of a twisted-nematic liquid crystal display (TNLCD). Both Yeh and Gu's transfer matrix and Lien's transfer matrix of a TNLCD are used and they are able to characterize all five cell parameters of a TNLCD including the cell gap, pretilt angle, rubbing angle, twist angle and untwisted phase retardation simultaneously. The optical setup is based on a single CCD camera and the ratio of p- and s-linear polarization intensity signals whereas we rotate a calibrated quarter wave plate to produce the polarization modulation during measurement. Thus, all five cell parameters are determined numerically by use of the least square curve fitting algorithm between the measured data and theoretical prediction following Yeh & Gu's and Lien's models of a TNLCD at same time. Finally, the advantages of this proposed IPMP are discussed.

A novel “degree of coherence paired surface plasma wave biosensor” (DOC-PSPWB) is proposed wherein the principle of detection involves the degree of coherence of highly correlated surface plasma waves when these are excited on a metal/dielectric interface within the DOC-PSPWB. Using the sensor, the concentration of total PSA (t-PSA) in a phosphate-buffered saline solution was measured, and a detection limit of 0.015pg/mL was determined experimentally. Finally, the dynamic range of the DOC-PSPWB when used on samples with ultralow molecular concentrations is discussed.

Among the parameters that affect photolithography, the most important are exposure and development time which affect the coating photoresist characteristics. This study further researches the relationship between the exposure and development time using a high speed image inspection system, and the relationship between the development time and photoresist depth using a Scanning Probe Microscope (SPM). A partial scan CCD camera and high speed frame capture card were used to obtain the photoresist development processing parameters. The experimental results verified that this imaging system provides an economical and effective method for producing a micro‐photo‐etched product. It is expected that these experiments can also offer some good references useful in the micro electro mechanical industrial field.

A new device, which combines the technologies of laser shadow spot and optical strain gauge with image processing, computer voice, and WWW software for detecting the broken procedure of different materials, has been presented in this paper. The whole testing experiments are monitored by an imaging system and guided by the computer voice to predict the crack step by step. The system generates a laser shadow spot or diffraction image on a screen when the laser beam passes through a lens as well as the crack gap of a specimen. The mechanical shelf changed the strength of the specimen and a CCD camera grabbed the variant images of the specimen under strength. The computer calculated each image for guiding the operator how to install the specimen and added the proper strength. Our proposed algorithm calculated the radius of the crash gap, the factors of the strength intensity and the strain value. In the experiment of optical strain gauge, the change in diffraction pattern and strain is caused by the applied force change. In the laser shadow spot experiment, the more the stress on the specimen causes the more the strain intensity factor and the later turns to saturation gradually, which means the specimen will be broken. � 2004 Elsevier Ltd. All rights reserved.

Degree of coherence (DOC) of a paired surface plasma waves (PSPWs) in the paired surface plasma waves biosensor (PSPWB) is proposed and discussed in which a paired of surface plasma waves are excited by using a pair of highly spatial and temporal correlated P-polarized waves in a SPR device of the Kretschmann configuration. The heterodyne signal from reflected paired P-polarized laser beam is generated where the visibility of the signal is proportional to DOC of PSPWs in term of the ratio of AC and DC components of the signal. The experimental result shows that the DOC of PSPWs versus incident angle of laser beam which relates to intrinsic phonon distribution in metal film becomes much sensitive than conventional amplitude or intensity sensitive surface plasmon resonance (SPR) biosensor. Finally, the dynamic range of protein-protein interaction at ultralow concentrations is discussed.

Viscoelastic shear waves (VESW) propagation in soft matters such as gelatin under thermal steady state was studied. VESW in a slab of gelatin causes the transverse displacement of the surface in a harmonic wave. The harmonic oscillation frequency of the transverse displacement of gelatin surface was then measured in real time in order to measure the modulus of rigidity of gelatin in terms of the measured oscillation frequency. A polarized heterodyne interferometer (PHI) was setup in this experiment which enables to precisely measure the transverse displacement of surface in real time at 0.3 nm resolution. This results in the proposed VESW method able to characterize gelatin soft material in real time. From the experimental demonstration, the properties of VESW propagation in soft material at thermal steady state potentially can become a novel nano-scale non-intrusion strain-stress sensor able to characterize the modulus rigidity of soft material.

Thermal elastic shear wave (TESW) propagating in dermis becomes harmonic wave because of partially isotropic and homogeneous conversion induced by ionization radiation damage. The linearity of absorbed dose versus transverse oscillation frequency of TEWS was measured.

We developed a novel differential-phase optical coherence reflectometer (DP-OCR) by using a low-coherence light source and integrated with differential phase detection technique on surface profile measurement. In this setup, 2A on detection of axial displacement was demonstrated. Thus, a localized surface profile was measured precisely by scanning an optical grating surface in this measurement. Moreover, the requirement on equal amplitude of the reference and signal beams of this novel reflectometer is discussed.

We demonstrated the generation of an inhomogeneously polarized laser beam using a triangular path interferometer in which only commercially available optical components were used. After a two-lobed transverse electromagnetic (TEM) laser mode impinged into the interferometer, a doughnut mode appeared at the exit of the interferometer, and the azimuth of polarization was 45° with respect to the radius. This mode was then converted into a radially polarized beam using a polarization rotator. The polarization purity of the converted beam was characterized by polarization analysis, and the characterization results showed good agreement with the theory.