Abstract: In measurement requiring application of pressure to a tissue of a living body such as blood pressure measurement, noise due to vibration tends to occur. It is therefore difficult to accurately measure a pulse wave and a blood pressure value, and there is a problem of measuring blood pressure stably. It is also difficult to measure blood pressure in daily life activities or to measure blood pressure at predetermined intervals or continuously in a state where a tonometer is always attached. There is consequently a problem of providing a method of holding a biologic information detecting apparatus. The present invention has been achieved to solve the problems and an object of the invention is to provide an easy-to-wear biologic information detecting apparatus for stably detecting biologic information.

Abstract: An object of the present invention is to provide a noninvasive constituent concentration measuring apparatus and constituent concentration measuring apparatus controlling method, in which accurate measurement can be performed by superimposing two photoacoustic signals having the same frequency and reverse phases to nullify the effect from the other constituent occupying large part of the object to be measured. The constituent concentration measuring apparatus according to the invention includes light generating means for generating two light beams having different wavelengths, modulation means for electrically intensity-modulating each of the two light beams having different wavelengths using signals having the same frequency and reverse phases, light outgoing means for outputting the two intensity-modulated light beams having different wavelengths toward a test subject, and acoustic wave detection means for detecting an acoustic wave generated in the test subject by the outputted light.

Abstract: An optical amplification medium doped with Er3+ ions is selected from the group of a fluoride glass, a chalcogenide glass, a telluride glass, a halide crystal, and a lead oxide based glass. The Er3+ ions are excited by light of at least one wavelength in the range of 0.96 &mgr;m to 0.98 &mgr;m. A laser or an optical amplifier includes this optical amplification medium doped with Er3+ ions. Furthermore, an optical amplification method performs an optical amplification using the optical amplifier having the optical amplification medium doped with Er3+ ions. Thus, the laser to be applied in the field of optical communication, the optical amplifier having the characteristics of low noise and high gain, and the optical amplification method can be provided.

Abstract: An optical amplification medium doped with Er3+ ions is selected from the group of a fluoride glass, a chalcogenide glass, a telluride glass, a halide crystal, and a lead oxide based glass. The Er3+ ions are excited by light of at least one wavelength in the range of 0.96 &mgr;m to 0.98 &mgr;m. A laser or an optical amplifier includes this optical amplification medium doped with Er3+ ions. Furthermore, an optical amplification method performs an optical amplification using the optical amplifier having the optical amplification medium doped with Er3+ ions. Thus, the laser to be applied in the field of optical communication, the optical amplifier having the characteristics of low noise and high gain, and the optical amplification method can be provided.

Abstract: This invention relates to fluoride glass with a specific composition having wide infrared transmission. A fluoride optical fiber using this fluoride glass can give high efficiency with a low loss. The fluoride optical fiber having a second cladding on the outer periphery of a first cladding can adjust the refractive index of the first cladding suitably.

Abstract: An amplifying optical fiber includes a core containing Tm ions as activation ions and a clad containing at least one of Tb ions and Eu ions. Alternatively, the amplifying optical fiber includes a core composed of more than two layers. Tm is contained in more than one of the more than two layers as activation ions and at least one of Tb ions and Eu ions is contained in more than one of the more than two in which Tm is not contained.

Abstract: Fluoride glass-based optical fiber for an optical amplifier which contains rare earth metal ions in the core glass has a relative refractive index difference .DELTA.n between the core and the cladding of 1.4% or more. The core glass contains PbF.sub.2 in a proportion of 25 mol % or less based on the total composition of the core glass. The fluoride glass is doped with rare earth metal ions, and part of the fluorine in the glass may be substituted by at least one halogen Pr.sup.3+, Pr.sup.3+ --Yb.sup.3+, Pr.sup.3+ --Nd.sup.3+, or Pr.sup.3+ --Er.sup.3+ can be doped as the rare earth metal ions. Chlorine, bromine or iodine may be used as the halogen.

Abstract: Fluoride glass-based optical fiber for an optical amplifier which contains rare earth metal ions in the core glass has a relative refractive index difference .DELTA..sub.n between the core and the cladding of 1.4% or more. The core glass contains PbF.sub.2 in a proportion of 25 mol % or less based on the total composition of the core glass . The fluoride glass is doped with rare earth metal ions, and part of the fluorine in the glass may be substituted by at least one halogen. Pr.sup.3+, Pr.sup.3+ --Yb.sup.3+, Pr.sup.3+ --Nd.sup.3+, or Pr.sup.3+ --Er.sup.3+ can be doped as the rare earth metal ions. Chlorine, bromine or iodine may be used as the halogen.

Abstract: Methods and apparatus are shown for cladding grown single crystal optical fibers. Neodymium YAG fibers are clad with a high index glass, either melted around the fiber in a trough or extruded over the fiber surface. Lithium niobate fibers are clad through an impregnation process. The lithium niobate fiber is first coated with magnesium oxide and then heated to a temperature and for a time sufficient for the magnesium oxide dopant material to diffuse into the fiber. The dopant lowers the intrinsic refractive indices of the fiber material around its circumference, creating a cladding region around the fiber core. Single crystal fibers clad by these methods and combined with suitable pumping means or with deposited electrodes provide low-loss single mode optical components useful for amplification, electro-optical effects and acousto-optical effects.

Abstract: Methods and apparatus are shown for cladding grown single crystal optical fibers. Neodymium YAG fibers are clad with a high index glass, either melted around the fiber in a trough or extruded over the fiber surface. Lithium niobate fibers are clad through an impregnation process. The lithium niobate fiber is first coated with magnesium oxide and then heated to a temperature and for a time sufficient for the magnesium oxide dopant material to diffuse into the fiber. The dopant lowers the intrinsic refractive indices of the fiber material around its circumference, creating a cladding region around the fiber core. Single crystal fibers clad by these methods and combined with suitable pumping means or with deposited electrodes provide low-loss single mode optical components useful for amplification, electro-optical effects and acousto-optical effects.

Abstract: A method of stabilizing the frequency of a semiconductor laser comprises stabilizing a time-dependent frequency fluctuation by utilizing an optical energy absorption medium including an isotope acetylene gas molecule. An apparatus for stabilizing the frequency of a semiconductor laser, comprises a semiconductor laser, an optical energy absorption medium, a photodetector and a control circuit as essential elements. The optical energy absorption medium includes an isotope acetylene molecule.