LASER SPECTRAL ANALYSIS OF STRAIN MEASUREMNT

Modern opticai theory has shown that the far field or Fraunbofer diffraction equipment is identical to the Fourier spectral analyzer. In the Fourier speetral analyzer the Fourier spectra or the Fraunhofer diffaction pattern of a graph is formed on the back focal plane when a laser beam is directed on the graph lying on the front foeal plane ; the Fourier spectra of the graph is also subjected to change during the deformation of the graph. Through analyzing the change of Fourier spectra the deformation of the graph can be obtained. A few years ago,based on the above principles the authors proposed a new technique of strain measurement by laser spectral analysis. Demonstration and discussion will be made in detail in this paper.

Profile Method for Measuring Apparent Optical Parameters (AOP) Ⅱin Class- Waters

The profile method is the principal method first to be chosen to measure the apparent optical parameters of waters. This paper first introduces the profile method briefly, then modifies Ⅱthe applied algorithm in the light of the properties of the class- waters and lastly, analyses the effect of application.

High Accuracy Zoom Magnification Measurement

A precise zoom magnification is important for semiconductor industry and biomedical research. A novel measurement method is demonstrated for optical zoom magnification measurement in this paper. The magnification is obtained by pattern correction between barcode image formed by optical zoom and reference image generated by an ideal optical model. Measurement accuracy which is better than 0.06% has been achieved for optical zoom magnification. Compared with traditional concept, the measurement results are only dependent on two line edges. The barcode correlation method can achieve higher accuracy and better robustness by using the information over the whole field of view.

Technology for the next gravitational wave detectors

This paper reviews some of the key enabling technologies for advanced and future laser interferometer gravitational wave detectors, which must combine test masses with the lowest possible optical and acoustic losses, with high stability lasers and various techniques for suppressing noise. Sect. 1 of this paper presents a review of the acoustic properties of test masses. Sect. 2 reviews the technology of the amorphous dielectric coatings which are currently universally used for the mirrors in advanced laser interferometers, but for which lower acoustic loss would be very advantageous. In sect. 3 a new generation of crystalline optical coatings that offer a substantial reduction in thermal noise is reviewed. The optical properties of test masses are reviewed in sect. 4, with special focus on the properties of silicon, an important candidate material for future detectors. Sect. 5 of this paper presents the very low noise, high stability laser technology that underpins all advanced and next generation laser interferometers.

Chemometrics-assisted excitation-emission fluorescence spectroscopy for simultaneous determination of ethoxyquin and tert-butylhydroquinone in biological fluid samples

A novel method applying simple, rapid, effective and inexpensive excitation-emission matrix （EEM） fluorescence spectroscopy coupled with second-order calibration method for simultaneous determination of ethoxyquin （EQ） and tert-butylhydroquinone （TBHQ） contents in biological fluid samples was developed. After a simple data preprocessing that was to insert zeros below the first-order Rayleigh scattering, the second-order calibration method based on the alternating normalization-weighed error （ANWE） algorithm was used to deal with EEM data. Via the introduced ＂second-order advantage＂, the individual con- centrations of the analytes of interest could be obtained even in the presence of uncalibrated interferences. The experimental concentration ranges for the analytes were as follows： EQ, from 4.58 to 20.6 p.g mL-1 in plasma and from 6.87 to 20.6 gg mL-1 in urine; TBHQ, from 4.49 to 20.2 ~tg mL-1 in plasma and from 6.73 to 22.4 I.tg mL-l in urine. The recoveries from spiked bi- ological fluid samples were in the ranges of 92.8%-106.2% for EQ and 94.6%-107.2% for TBHQ. These results demonstrate that the three-dimensional EEM fluorescence with second-order calibration method is a powerful tool for obtaining both EQ and TBHQ quantitative results in plasma and urine samples, and could be applied to more complex matrices.

Measurement of the applanated diameter of ocular cornea using a novel optical probe

A precise measurement of the applanated diameter of the ocular cornea with the optical probe is very important in applanation tonometry.A novel optical probe with a common path configuration is presented.The optical probe mainly consists of a cone-shaped prism and a photodetector.The former serves as a measuring body touching the ocular cornea to shape the area to be measured,and the latter converts the quantity of the luminous flux returning from the cone-shaped prism into one electronic current signal.Laboratory experiments are carried out on a simulated eyeball,followed by an enucleated porcine eyeball specimen.Experimental results show that there is a significant rise of the normalized variational current with increasing the applanation diameter of the ocular cornea,and the sensitivity is 0.2111/mm with an error of 0.00263/mm.Measurements of the normalized variational current on the porcine eyeball have good agreement with those on the simulated eyeball.