| 摘要 |
PROBLEM TO BE SOLVED: To provide microscopy utilizing a technique for exciting three or more photons of an object containing a molecule which can be excited by a photon having characteristic energy. SOLUTION: A laser scanning microscope brings about intrinsic three-dimensional resolution by causing molecular excitation in the object by simultaneously absorbing three or more photons. A phosphor having single-photon absorption in a short (ultraviolet or visible) wavelength region is excited with a strongly image-formed sub-picosecond pulse beam composed of laser light in a relatively long (red or infrared) wavelength region. The phosphor absorbs light even when the light has a wavelength which is about a third wavelength, quarter wavelength, or a smaller fractional number of the wavelength of the laser light for preparing the fluorescent image of a living cell or other extremely fine objects. The fluorescent radiation from the phosphor increases in a cubic, quadratic, or a larger power rule and, consequently, not only light bleaching but also fluorescence can be restricted to the vicinity of a focal surface by causing the laser light to form an image. This feature gives a visual field resolution depth matching that which is brought about by a confocal laser scanning microscope and, in addition, reduces the light bleaching and the toxicity of light.
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