Two types of environmental applications for fiber-optic sensors are presented. First, development of a long-length remote Raman probe, and second, a series of new fiber-optic temperature sensors are presented.; A long-length fiber-optic remote Raman probe that can detect materials (e.g. Fe{dollar}sb2{dollar}O{dollar}sb3){dollar} which are weak Raman scatterers is described. The 100 meter long probe consists of one excitation and one collection fiber and accessory optics and is less than 3 mm in diameter. Special filters solve the problems of Raman scattering and luminescence generated in the silica excitation and collection fibers, and a liquid nitrogen cooled charge-coupled detector (CCD) allows analysis of weak Raman signals. A theoretical examination is given for optimization of a dual fiber remote Raman probe. Two applications are given. First, as an optical analysis method for determining current and voltage conditions for an electrical conductor "arc point," and second, as a monitoring system for glass-forming processes in high temperature furnaces.; A series of new fiber optic temperature sensors are also proposed. One design uses the fluorescent emission amplitude of inorganic ions doped in a host matrix in the near infrared region as the temperature determining method and graded index fiber optics as the transmission medium. Four materials are investigated: Nd{dollar}sp{lcub}3+{rcub}{dollar}:Glass; Er{dollar}sp{lcub}3+{rcub}{dollar}:Glass; Cr{dollar}sp{lcub}3+{rcub}{dollar},Er{dollar}sp{lcub}3+{rcub}{dollar}:Y{dollar}sb3{dollar}Sc{dollar}sb2{dollar}Ga{dollar}sb3{dollar}O{dollar}sb{lcub}12{rcub}{dollar}; and Nd{dollar}sp{lcub}3+{rcub}{dollar}:Gd{dollar}sb3{dollar}Sc{dollar}sb2{dollar}Al{dollar}sb3{dollar}O{dollar}sb{lcub}12{rcub}{dollar}. Feasibility in the design of a 10 km length point sensor with an accuracy of {dollar}pm{dollar}0.2{dollar}spcirc{dollar}C between 0{dollar}spcirc{dollar}C and 300{dollar}spcirc{dollar}C is presented.; The other design uses fluorescent decay of selected materials as the temperature sensing mechanism. These sensors employ "time-domain" fluorescent decay analysis of ruby and Rhodamine dye as the temperature sensing medium. From this work, a new series of OTDR's have also been developed using spontaneous Raman scattering as the measurement device.
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