Human teeth fluoresce as a result of illumination by UV-light. The fluorescence characteristics of human teeth were investigated with respect to aging using microscope fluorometry. To measure nanoscecond decay features of a tooth's fluorescence, a microscope fluorometer equipped with an air-discharge pulsed lamp was devised. The fluorescence intensity and fluorescence decay curve were found to be age dependent in dentin tissue; the fluorescence intensity increased and the fluorescence decay time decreased with increasing human age. Ancient teeth showed more intense fluorescence with a shorter decay time than that of the modern teeth. This may result from a gradual maturation of fluorescent cross-linked collagen, which increases with age.
We succeeded in the experiments of the optical trapping and optical rotation of small particles by use of radiation pressure and the angular momentum of circularly polarized laser beam. The trapping was made two-dimensionally in the sample space of the optical microscope; The rotation of the sample was observed through the micloscope eye pieces. A heimispherical polystyrene latex of 7 μm diameter was rotated at the rate of 48 second per one turm by 514.5 nm wavelength 5 mW Argon-ion laser. Experimental apparatus and conditions are described and the results are analyzed, and discussed. The future applications of this technique are also discussed.
Confocal microscope system, which has higher resolution than an ordinary microscope, has spectrometric capability with no special optical elements. It is found by calculation that the confocal microscope system with SFS1 lens which has 20.9 aberration number has 0.6 nm spectral resolution. This report describes about some applications of the system.