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Optical back-scattering from milk with various fat and protein concentrations were evaluated in a back-scattering configuration using white, violet, blue, green, red or near infrared (NIR, λ = 850 and 940 nm) LEDs as the light source. The tip of the optical fibre bundle was dipped into the milk with fat and protein concentrations from 8.2 to 39 g L−1 and 32 to 37.7 g L−1, respectively. The back-scattering intensities varied linearly with the fat and protein concentrations of the milk. The slope (G) of calibration lines varied with the wavelength of the incident light. The G of the fat concentrations became zero at wavelength around λ = 520 nm and that of the protein concentrations was much smaller than that of the fat concentrations at NIR wavelengths. The fat and protein concentrations can therefore be measured separately based on the scattering intensities by selecting the wavelength for measurement.

A novel thermoelectric type hydrogen gas sensor based on exothermic reaction of hydrogen storage alloy is proposed and fabricated. First, an exothermic reaction of a hydrogen storage alloy at room temperature has been studied for a hydrogen gas sensor application. Next, a copper (Cu) constantan thermocouple painted a palladium (Pd) past on surface was fabricated as a hydrogen gas detector. The response characteristic of the fabricated hydrogen gas detector was evaluated under hydrogen gas flow. The exothermic reaction of Pd and hydrogen gas was successfully observed using fabricated gas detector. It was clarified that the fabricated hydrogen gas detector using Cu constantan thermocouple with Pd is potentially useful for hydrogen gas sensor material.

Thermo-sensor characteristics of Cr doped YAlO3 composite with silicone resin have been evaluated based on the temperature dependence of photoluminescence intensity from the specimens. Photoluminescence (PL) peaking at wavelengths, λ = 725, 732 and 748 nm are observed from the composite sensor with an excitation by green colored LED at λ = 536 nm. PL peak intensities and peak intensity ratio varies sensitively with temperature. Silicone composite sensor with 50 wt% of 0.2 at% Cr doped YAlO3 powders is found to be useful sensor for fluorescence thermometer, because of the large temperature coefficient and good repeatability of PL intensity ratio.

Luminescence properties of Mn doped MgAl2O4 crystals connected with the Si PIN photodiode (PD) have been evaluated for X-ray detector applications. Mn doped MgAl2O4 crystals emit green colored luminescence peaking at around λ = 520 nm with CuKα irradiation. The intensity of the output signal from Si PD increases linearly with the X-ray intensity of CuKα generated with the X-ray tube at a current from 2 mA to 40 mA. The intensity of the X-ray excited luminescence is strongest in the specimen with 3.0 mol. % Mn. Afterglow luminescence is weak in the specimen with 2.0 mol. % Mn. Mn doped MgAl2O4 crystals connected with the Si PD is considered to be a useful X-ray detector.

A new compound having a 2,3,4,5-tetraphenylsilole derivative on the center silicon of Dumbbell(1)6Gb3; Silole-Dumbbell(1)6Gb3 (1) was previously reported. It was found that 1 exhibited strongly increased fluorescence both in water and in a 96% acetone/water mixed solvent. The physical behavior of 1 in water and in the 96% acetone/water mixed solvent was investigated, and analyses including fluorescence quantum yields, dynamic-light-scattering (DLS), atomic-force-microscopy (AFM), and fluorescence microscopy were carried out. It was clarified that 1 dynamically formed different types of aggregates in water and in higher acetone concentrations to yield high aggregation-induced emission (AIE) effects due to the formation of micelle-like particles in water and inversion-type micelles in the acetone/water mixed solvent, respectively.

A glycocluster peripherally functionalized with a lactose (Lac: Galβ1→4Glcβ1–) derivative possessing a silole moiety as a luminophore was synthesized. The photoluminescence spectrum of the glycocluster showed extremely strong emission at 474 nm and the absolute quantum yield was estimated to be 92% in distilled water. The emission intensity was decreased by increasing the amount of peanut agglutinin (PNA), a lactose-binding lectin, and plots of the relative fluorescence intensity revealed a decline of 95% in emission intensity. Fluorescence quenching of the glycocluster upon mixing with PNA could be easily observed by the naked eye under UV irradiation, whereas no distinct change in fluorescence properties of the glycocluster was observed when wheat germ agglutinin (WGA) was employed.

A novel glycocluster periphery functionalized by globotriaose (Galα1–4Galβ1–4Glcβ1–) possessing a silole moiety as a luminophor was synthesized. The photoluminescence spectrum of the glycocluster in pure water showed extremely strong emission at 475 nm. Analogous intense emission of the silole dendrimer was also observed in a lower water fraction of water/acetone mixture. The water fraction of the silole dendrimer solution strongly affected the emission intensity; however, these luminescences were constantly detected at around 475 nm.

Rare-earth aluminate crystals have chemical and thermal stability, which are advantage for the sensor materials of a fiber-optic fluorescence thermometer. Among many rare-earth aluminate crystals, rare-earth garnet, Y 3 Al 5 O 12 , doped with Cr 2 O 3 (Cr-doped YAG), is found to be useful as the sensor materials for fluorescence thermometer. Fluorescence lifetime of Cr-doped YAG crystal decreases from 2 ms to 0.1 ms as the temperature increases from 273 K to 900 K. Moreover, thermal radiation from Cr-doped YAG crystal can be observed from 800 K using Si photo-detector. The fiber-optic thermometer with extremely wide temperature range is considered to be produced by the combination of the temperature dependence of the fluorescence lifetime and the thermal radiation from Cr-doped YAG crystal.

Terbium ion (Tb 3+ ) doped silica glass (Tb:SiO 2 ) and yttrium aluminum garnet crystals (Tb:YAG) have been fabricated for the applications in fiber-optic thermometers based on the temperature dependence of the photoluminescence (PL) spectrum. Several PL peaks at 490, 540, 585, 625 nm were observed from both Tb doped phosphors. In Tb:YAG crystal, the PL peaks were split into two or three small peaks due to the Stark effect. Temperature dependence of PL spectra from Tb:SiO 2 glass and Tb:YAG crystal was evaluated over a temperature range from 300 to 1200 K. In the Tb:SiO 2 glass, the peak PL intensity varied greatly with temperature. The shape of the PL spectrum from Tb:YAG crystal varied with temperature because the resolution of the split in the peak PL decreased with temperature. The intensity ratio between splitting PL peaks, therefore, varied with temperature. From these results, Tb:SiO 2 glass and Tb:YAG crystals are considered to be a useful sensor head materials for high temperature measurement using temperature dependence of PL intensity.

Temperature dependence of photoluminescence (PL) peaking at wavelength of λ = 440 nm from FZ grown CaAl 2 O 4 ; Eu, Dy phosphor crystal is evaluated for a fiber-optic thermometer application. The PL lifetime from the specimens decreases greatly from 11.24 to 1.17 ms as the temperature increases from 305 to 458 K. The temperature coefficient of PL lifetime, - 0.17 ms / K , in the narrow temperature range from 305 to 345 K is larger than that of ruby (Cr doped Al 2 O 3 ) whose PL lifetime is 4 ms and temperature coefficient is - 0.169 ms / K . The large temperature coefficient of PL lifetime of CaAl 2 O 4 : Eu, Dy phosphor crystal is due to the trap levels generated by Dy doping.

A fibre-optic thermometer using newly developed phosphor sensor materials is described. A highly sensitive fibre-optic fluorescence thermometer is developed using chromium ion (Cr3+) doped phosphor crystals with a longer lifetime than that of conventional ruby sensors. Long fluorescent europium doped strontium aluminate phosphors co-doped with various auxiliary activators (SrAl2O4:Eu2+, Ln3+, Ln = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), were also grown and evaluated. In the fibre-optic thermometer using Cr3+ doped phosphor, PL lifetime decreased at temperatures ranging from 270 K to 750 K. The sensitivity of the fibre-optic thermometer varies with the host materials of Cr3+ ions. In the fibre-optic thermometer using SrAl2O4:Eu2+, Ln3+ doped phosphor, the value and lifetime of afterglow phosphorescence from the SrAl2O4:Eu2+, Ln3+ phosphors varied greatly in the narrow temperature region because the afterglow phosphorescence was dominated by thermal excitation of trapped carriers. Since the trap depth and the trap density depend on auxiliary activator elements, the sensitivity and temperature range of the fibre-optic thermometer using SrAl2O4:Eu2+, Ln3+ phosphors varied with auxiliary activator elements of SrAl2O4:Eu2+, Ln3+ phosphors.

The chromium doped spinel crystals, MgAl2O4:Cr3+, have been grown using floating zone technique and its application for the fiber-optic thermometer is discussed on the basis of the temperature dependence of the fluorescence lifetime. Lifetimes of the spinel crystals (τ=10 ms), which decrease with temperature, were about 3 times larger than that of the ruby crystals (τ=4 ms) at room temperature. Temperature coefficients of the photoluminescence (PL) lifetimes for spinel crystals (37 μs/K) are also 3 times longer than that for the ruby crystals (10 μs/K). The spinel crystals are potentially useful sensor probes for the fiber-optic thermometer, which have an advantage of high sensitivity due to long PL lifetime and large temperature coefficient.

A carbosilane dendrimer (4a) and its silacyclopentadiene analog (4b), both functionalized with lactoses, were tested for their abilities to act as drug-delivery systems. The critical micelle concentrations of 4a and 4b were measured using the drop-volume method in water and were 1.7 and 2.9 μM, respectively, suggesting that they could act as aggregates of glycoclusters. The amounts of the hydrophobic dye Orange OT loaded onto aqueous micelles of 4a and 4b and the stabilities of the dye/micelle complexes were determined by extracting the dyes from the complexes into chloroform. The particle sizes were measured for the loaded micelles by dynamic light scattering. Transfer of the dye from the micelles to peanut agglutinin was observed by fluorescence microscopy. Given the abilities of micelles of 4a and 4b to bind and release Orange OT, these glycocluster micelles may find use as drug-delivery systems.

A TiO2:Nd formed on Si(100) substrate by laser ablation. The TiO2:Nd shows IR emissions at room temperature. The superconducting magnet was used for applied of a magnetic field. Magnetic field intensity was changed from 0.0 T (Tesla) to 8.0 T with PL measurement at room temperature. The sharp intense PL peak at 913.5 nm, 933.3 nm, 954.6 nm, 1093.7 nm and 1382.7 nm originating from the intra-4f shell transition in Nd3+ ions was observed. The spectrum form change was according to the Zeeman effect with the rise of magnetic field intensity.

The magnetic field dependence of photo luminescence (PL) peak split and peak intensity rate from Nd doped YAG crystal was studied for the optical-magnetic sensor application. Photoluminescence peaking at the wavelength from 800 nm to 1400 nm are observed in Nd doped YAG crystal at room temperature. The feature of these PL peaks split with magnetic field. Peak intensity rate and Peak split of PL from Nd doped YAG crystal linearly with the magnetic field increasing from 0.0 T to 8.0 T at room temperature. Fluorescence optical magnetic sensor system using fluorescence sensor crystal enables non-contact magnetic field measurements.

Temperature dependence of peak intensity and peak intensity ratio of photoluminescence (PL) from composite thermo-sensor with Cr doped garnet crystal (YAG) is evaluated for fluorescence thermometer. Peak intensity of PL decreases with temperature. Intensity ratio of PL peaks increases linearly with temperature from 300 to 500 K. Composite sensor with Cr doped YAG is potentially useful sensor material in fluorescence thermometer based on temperature dependences of PL intensity ratio.

Fluorescence oxygen gas sensor using photo quenching with oxygen molecule was characterized. The quenching ratio of fluorescence from an organic fluorescence dye is proportional to oxygen partial pressure by the Stern-Volmer's formula. The oxygen concentration, therefore, is estimated from the quenching ratio of fluorescence intensity. We have fabricated a fluorescent oxygen sensor chip (light emitting substance: aromatic compounds), characteristics of which was experimentally investigated as an oxygen concentration sensor in visible light. The relationship between the oxygen concentration and the intensity of fluorescence was measured in the vapor phases. The oxygen concentration in the vapor phases can be measured using the oxygen sensor chip by measuring the intensity of fluorescence.

Composite sensor mixed with long afterglow SrAl2O4:Eu,Ln phosphors and ruby have been developed for the fluorescence thermometer applications. Temperature can be measured based on the temperature dependence of photoluminescence (PL) intensity from mixed composite sensor. The temperature dependence of PL intensity and intensity ratio of PL from long afterglow phosphor and ruby is evaluated from PL spectra at various temperatures. Intensity ratio of PL peaks from different phosphors in the composite sensor is useful for temperature measurement.

Multi-channel pH sensor based on the color change from the organic dye was examined. Six pH indicators were selected for wide pH measurement range. Absorption spectra of the visible light were evaluated to six pH indicators. Moreover, pH valuation of the absorption spectra was evaluated for the optical pH sensor application.

Fluorescence thermometer based on peak intensity of photoluminescence (PL) is evaluated using Ti doped sapphire (Al2O3) crystal. Broad PL peak is seen at lambda=725 nm. PL peak intensity is found to be sensitive to temperature. Fluorescence thermometer based on temperature dependence of PL peak intensity is reported using Li doped sapphire crystal.

Fiber-optic thermal radiation thermometry was studied using Er end doped silica fiber sensor. Visible light radiation peaks were clearly observed at lambda=522 nm and, 655 nm, 800 nm and 984 nm from Er end doped silica fibers sensor. Theses peaks increase greatly with temperature of the sensor. Intensity ratio of thermally excited luminescence peaks at lambda=522 nm and 984 nm, I522/984, is suitable for the high temperature measurement. Two dimensional (2-D) temperature distributions in a flame are successfully visualized by X-Y scanning technique using Er end doped silica fiber sensor

Fluorescence sensor sheet has been fabricated successfully by Cr doped YAlO3 powder and silicone resin, and characterized for applications as the thermo-sensor material. Fluorescence thermometer system using fluorescence sensor sheet enables non-contact temperature measurement in extraordinary conditions. In this system, temperature measurement technique based on the temperature dependence of Photoluminescence (PL) intensity ratio is more convenient and practical system than that using temperature dependence of PL lifetime. Among many phosphors, Cr doped YAlO3 is found to be useful as the sensor materials for fluorescence thermometer sheet because of its long PL lifetime and large PL intensity. PL peaking at 740 nm, 742 nm, 744 nm and 750 nm are observed from the fluorescent sensor sheet with an excitation by a laser diode at lambda=405 nm. Temperature dependence of the PL intensity ratio, 1740/1750, which increases with temperature from 300 K to 440 K, is suitable for non-contact temperature measurement

Temperature dependences of peak intensity and peak intensity ratio of photoluminescence from Cr doped spinel sensor are evaluated for fluorescence thermometer applications. Peak intensity and intensity ratio of PL from Cr doped spinel sensor varies with temperature. Peak intensity ratio of PL at ?=699 and 688 nm, I699/I688, which increases linearly with temperature from 298 to 473 K, is found to be suitable for temperature measurement instead of PL lifetime. Spinel thermo-sensor is proposed successfully based on temperature dependence of PL intensity ratio instead of PL lifetime.

A composite of a long afterglow SrAl2O4 co-doped with Eu and Dy (SAOEuDy) powders and a silicone was fabricated in order to improve the water-resistance of the SAOEuDy phosphors. The phosphorescence characteristics of the SAOEuDy composite were measured for the variation of water temperature from 0degC to 100degC. In the temperature range, the phosphorescence intensity increases linearly with increasing temperature. This result indicates that the water-resistive SAOEuDy composite is useful sensor material

Temperature dependence of peak intensity and peak intensity ratio of photoluminescence (PL) from garnet crystal sensor is evaluated for fluorescence thermometer application. Peak intensity of PL from YAG sensor decreases exponentially with temperature. Intensity ratio of PL peaks at 690nm, 688nm and 688nm, I678 / I689, I707 / I689, I725 / I689, increases linearly with temperature from 299 to 473K. Cr doped YAG is potentially useful sensor material in fluorescence thermometer based on temperature dependences of PL intensity, and PL intensity ratio.

Variations in the photoluminescence (PL) spectra from porous silica gel containing the luminous organic pigments, which is sensitive to organic vapors, were evaluated at various temperatures. PL intensity from rhodamine and fluorescein contained silica gel decreases with temperature. Temperature coefficient of peak intensity from rhodamine and fluorescein contained silica gel is found to be different. In order to evaluate using rhodamine and/or fluorescein contained silica gel sensors, temperature must be controlled during measurement. Fluorescence thermometer is also suggested to be developed based on temperature dependence of photoluminescence from rhodamine and fluorescein contained silica gel sensors.

Fiber-optic sensor for fluoresce thermometer is developed using Eu end doped silica fiber. Fluorescence peaks were clearly observed at lambda=433 nm, 438 nm and 617 nm from Eu end doped silica fibers sensor. Peak increased linearly with temperature of the sensor. Intensity ratio of the peaks at lambda=433 nm and 617 nm, I433/617, also increased linearly with temperature of the sensor. Intensity ratio, I433/617, was suitable for the temperature measurement because of it is large temperature coefficient

Fluorescence thermometer based on the temperature dependence of phase angle of fluorescence pulse was developed using long afterglow SrAl 2 O 4 :Eu,Dy and SrAl 2 O 4 :Eu,Nd phosphors as the sensor materials. Phase angle sensitively varies with temperature. The phase angle measurement technique is potentially useful for the temperature sensing using long afterglow phosphors with extremely high sensitivity.

Thermal radiation from Y doped and Er doped SiO 2 fibers were studied for the fiber-optic thermometer application in high temperature. Thermal radiation similar to the black body radiation was observed in visible light region from the SiO 2 fibers doped with Y. Visible light radiation peaks due to f-f transitions of rare-earth ions were clearly observed in the Er doped SiO 2 fibers. Intensity ratio of thermal radiation at different wavelength is suitable for the highly sensitive temperature measurement. The hybridization of fluorescent thermometry and thermal radiation thermometry is suggested to extend the temperature range and increase the temperature resolution.

The effect of trap level in the europium doped strontium aluminate (SrAl/sub 2/O/sub 3/:Eu/sup 2+/) phosphors have been evaluated for the fiber-optic thermometer application. Sensitivity and temperature range of the SrAl/sub 2/O/sub 3/:Eu/sup 2+/ phosphor sensor head vary strongly with the trap depth and the trap density of the phosphors. In the temperature ranging from 273 K to 353 K, SrAl/sub 2/O/sub 3/:Eu/sup 2+/ co-doped with Dy/sup 3+/ or Nd/sup 3+/, which have trap depth at around Et=0.5 eV, is powerful sensor material having large temperature coefficient.

The intensity of afterglow phosphorescence and lifetime from the fiber-optic thermometer using long duration phosphor, SrAl/sub 2/O/sub 4/:Eu/sup 2+/,Dy/sup 3+/, have been evaluated. In the long phosphorescent sensor head, the intensity of afterglow phosphorescence increases greatly and linearly with the temperature ranging from 270 K to 320 K with the temperature coefficient of 1.3%/spl middot/K/sup -1/. Temperature coefficient of the afterglow intensity is found to be more sensitive than that of PL lifetime.

Thermometer probe using the chromium doped spinel crystals, MgAl/sub 2/O/sub 4/:Cr/sup 3+/, has been fabricated and the wavelength dependences of PL lifetime are evaluated as compared with those using ruby crystals. Lifetimes and temperature coefficients of the spinel crystals (/spl tau/=10 ms, 37 /spl mu/s/K), which were typically 3 times larger than that of the ruby crystals (/spl tau/=4 ms, 10 /spl mu/s/K), varied from 4.74 ms to 1.65 ms with wavelength from 667.5 nm to 780 nm.

This paper describes a fiber optic oxygen sensor using fluorescence and its application to industrial examinations. The quenching ratio of fluorescence is proportional to oxygen partial pressure by the Stern-Volmer's formula by which the oxygen concentration is possible to estimate from measured emission intensity. We have fabricated a luminous probe (light emitting substance: Solvent Green 5), characteristics of which were experimentally investigated as an oxygen concentration sensor in visible light.

Visible light thermal radiation from SiO2 glass doped with Y, La, Ce, Pr, Nd, Eu, Tb, Dy, Ho, Er, Tm, Yb, and Lu were studied for the fiber-optic thermometer application based on the temperature dependence of thermal radiation. Thermal radiations according to Planck's law of radiation are observed from the SiO2 fibers doped with Y, La, Ce, Pr, Eu, Tb, and Lu at the temperature above 1100 K. Thermal radiations due to f-f transitions of rare-earth ions are observed from the SiO2 fibers doped with Nd, Dy, Ho, Er, Tm, and Yb at the temperature above 900 K. Peak intensities of thermal radiations from rare-earth doped SiO2 fibers increase sensitively with temperature. Thermal activation energies of thermal radiations by f-f transitions seen in Nd, Dy, Ho, Er, Tm, and Yb doped SiO2 fibers are smaller than those from SiO2 fibers doped with Y, La, Ce, Pr, Eu, Tb, and Lu. Thermal radiation due to highly efficient f-f transitions in Nd, Dy, Ho, Er, Tm, and Yb ions emits more easily than usual thermal radiation process. Thermal radiations from rare-earth doped SiO2 are potentially applicable for the fiber-optic thermometry above 900 K.

A fluorescence thermometer using the temperature dependence of the phase shift of fluorescence response was developed using a ruby phosphor sheet. The ruby phosphor sheet was compounded of ruby powder and silicone resin. The fluorescence lifetime from the ruby phosphor sheet was measured with a phase shift measurement technique. The phase shift of the fluorescence response from the ruby phosphor sheet decreased linearly with temperature from 270to350K. The ruby phosphor sheet is found to be powerful tool for temperature measurement, and can be used for noncontact temperature measurement.

A fabrication process of the erbium (Er)-doped silica sensor probe, in which the sensor head is directly coupled with silica glass fiber, has been developed for the fiber-optic thermometer application. In this fabrication process, a droplet of slurry of Er-doped silica powders are formed on the end of the silica glass fiber, and are dried, sintered, and then melted and solidified in a LPG-O2 gas furnace. The temperature dependence of the photoluminescence (PL) lifetime from the Er-doped silica senor probe with various dopant concentrations has been evaluated for the fiber-optic thermometer application. An Er-doped silica sensor probe with an Er density above 10000ppm and aluminum (Al) content about Al∕Er=20 is considered to be suitable for a fiber-optic thermometer because of the strong PL intensity and long PL lifetime. The PL lifetimes of the Er sensor head decreases from 9.9msto8.1ms at temperatures from 273Kto473K. An Er-doped silica sensor probe, which is fabricated by a modified process, is consider...