A key technique of detecting the ultra-weak photon emission from biological system (UPE) is to change the light signal of an extremely weak level into electric signal of a considerable level when the photo-electric detecting system were be applied. This paper analyzed the difficult for detecting the ultra-weak photon emission from biological system (UPE) mainly is in the absence of high sensitivity detector in UV-visible-infra spectra region. An experimental setup for testing UPE in different spectral region was designed. Using the experimental setup the test data of different several spectral regions from 300 nm to 1060 nm has were tested. The test result show the UPE of living biological system exists in wide spectra region from UV- visible to infrared.
In the paper the research status and viewpoints about the coherent of the ultra-weak photon emission from biological system (UPE) were simply introduced. For proving the biophotons indeed have coherent from another side, an experimental setup for testing UPE in different spectral region was designed. Using the experimental setup the test data of different several spectral regions from 300nm to 1060nm has been got. These test results show that UPE of living biological system exists in wide spectra region from UV-visible to infrared. Using the test data, we also can obtain the important conclusion of UPE has coherence. In the end of this paper, the UPE's application in medicine was discussed.
Two key problems for designing laser scanning confocal microscopy (LSCM)are : 1 ) how to design a nice laser focusing system for getting the small focusing spot for iliminating object;2)how to design excellent microscopiel imaging systen for getting the poinat image which has high contrast .These problems decide the resoluion of LSCM. This paper anslysed the optical character of LSCM by Fourier theory and dicussed the effective confocal spot will depend the optics used, the aberration of optical system, and the size of pinhole Key words: laser,scanning system, confocal microscope, Fourier analyes,resolution
Using the changes of light absorption coefficient for measuring the ratio of haemoglobin and oxyhaemoglobin, the oxygen saturation can be calculated and has got successful applications. According to the spectroscopic characters of haemoglobin and oxyhaemoglobin, this paper presented a new system for monitoring the arterial oxygen saturation.
Recently the laser microbeam instrument has been used for wider applications in biological science and medicine. A key problem of the laser microbeam instrument is designing the laser focusing system for getting a focal spot size of less than 1 micrometer. This paper presents a new laser focusing system which is composed of a spatial filter and an 80X focusing objective lens. The 80X focusing objective lens was designed as a double reflective sphere type. Using this focusing system, the laser microbeam instrument has gotten a focal spot size of less than 0.5 - 1 micrometer. The focal spot size depends on the pinhole diaphragm diameter of the spatial filter. Different pinhole diaphragm diameters could produce different focal spots that are given in the end of this paper.
KEYWORDS: Photonic microstructures, Single photon, Near field optics, Microscopes, Particles, Optical fibers, Image resolution, Reflection, Scanning tunneling microscopy, Near field scanning optical microscopy
The foundation for the invention of the photon scanning tunneling microscope (PSTM) are the near field scanning optical microscope, the optical fiber technique, the total internal reflection, high sensitive opto-electronic detecting technique and computer technique etc. Recent research results show the subwavelength resolution of 1 - 3 nm is obtained. How to explain the PSTM has got such high subwavelength resolution? What value is the PSTM's limiting of subwavelength resolution? For resolving these problems this paper presented a photon theory hypothesis about PSTM that is based on the following two basic laws: (1) Photon is not only a carrier bringing energy and optical information, but also is a particle occupied fixed space size. (2) When a photon happened reflection, refraction, scattering, etc., only changed its energy and optical information carried, its particle size doesn't change. g (DOT) pphoton equals constant. Using these two basic laws to PSTM, the `evanescent field' is practically a weak photon distribution field and the detecting fiber tip diameter is practically a `gate' which size controlled the photon numbers into fiber tip. Passing through some calculation and inference, the following three conclusions can be given: (1) Under the PSTM's detection system sensitivity is high enough, the diameter D of detecting fiber tip and the near field detecting distance Z are the two most important factors to decide the subwavelength resolution of PSTM. (2) The limiting of PSTM's resolution will be given upon the conditions of D equals pphoton and Z equals pphoton, where pphoton is one photon size. (2) The final resolution limit R of PSTM will be lim R equals pphoton, D yields pphoton, Z yields pphoton.
A new type of laser-fiber sensor for measuring and monitoring a big size body (for example the rocket body) surface's relative shift, which is produced in a strong vibration system, has been studied. The laser-fiber sensor is a combination of laser, fiber, computer, etc. and has features of simple, quick, and high accuracy. The light of a semiconductor laser with a wavelength of (lambda) equals 780 nm passes through a 12 m long multi-mode fiber and an objective lens, then irradiates on the surface measured. Another objective lens collects the reflected light from the surface measured and images it on a 2048 charge coupled device (CCD), then a 286 computer processes the signal from the CCD. The sampling frequency of measuring data of this laser-fiber sensor is 800 Hz and its measuring accuracy is better than +/- 0.05 mm. The measuring range of relative shift is about +/- 15 mm. It has the ability to measure and monitor the related shift of moving objects in a strong vibration system.
Multiple diffraction rings are observed after a pulse laser beam passes through an absorbing dye LB film. The theoretical analysis, based on the model of transverse self-phase modulation, is also given. The saturated nonlinear refractive index n2 is estimated to be 2.0 X 10-8 cm2/W from the number of rings induced in the LB films. The main contribution to this larger nonlinearity is believed to be from laser-induced transformation between H-aggregates and monomers of molecules in the LB films.
We report an observation of optical phase conjugate and high-order diffractions from degenerate multi-wave mixing in LB films of pure purple membrane for the first time. Based on the simplified BR photocycle, a model that describes the high-order diffractions from the population gratings versus the total incident intensity has been developed. The saturated absorption intensity and the saturated nonlinear refractive index of the LB films have been estimated by fitting method to be 0.42 W/cm2, and 5 X 10-2 cm2W, respectively. The typical response time of its nonlinearity is about several milliseconds.
Using double-reflective spheres, a UV focusing objective with short focal length and long working distance was designed. This UV focusing objective could work in a wide wavelength range and has the property of antilaser damage. It was applied successfully in a laser focusing system with a spatial filter, with some interesting results.
The development of an information-theoretic image measure for sensor evaluation, under contract to the United States Air Force, is described. Although current approaches are based on human perception models, a need exists for evaluation of sensors for automatic target cuing/automatic target recognition (ATC/ATR) systems. Such an evaluation should be performed in terms of the probabilities of detection/identification and false alarms, independent of the idiosyncrasies of the specific ATC/ATR algorithms. Such an approach based on the information-theoretic content of images for the target versus background separability is being developed and applied to evaluating sensors using the tower test data collected at the Wright Laboratories.
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