Optical fibers thin film deposition

S. Zhao and W. M. Reichert, Modeling of fluorescence emission from cyanine-dye-impregnated Langmuir-Blodgett films deposited on the surface of an optical fiber, Thin Solid Films 200, 363-373... 

Instrumentation. A setup employing an ITO-coated glass sheet as the working electrode and ATR element as shown in Fig. 5.12 has been proposed for studies of thin films deposited on the ITO layer [64]. Light is piped through an optical fiber to... 

The samples are usually prepared as thin films deposited on a suitable support (e.g., a glass slide), plates, or powders. However, by utilizing special accessories (e.g., optical fiber probes) and instrumental setups, in principle one can perform photoluminescence experiments on any object. As a consequence of the front-face geometry and the low transparency of the sample, it is often the case that luminescence measurements on solids involve only the outer part of the sample, for a depth on the order of a few micrometers or less. Therefore, particularly in the case of powdered samples, it is important to obtain a homogeneous dispersion of the granules and deposit it as a thin layer on a transparent support, such as glass or quartz, potentially utilizing an inert medium like mineral oil. 

Developing better processes for deposition and coating of thin films. An integrated circuit, in essence, is a series of electrically coimected thin films. Thin films are the key stractural feature of recording media and optical fibers, as well. 

The developed sensor was used for ultrathin-film measurement. The reflection spectrum was shifted during the deposition of thin films (e.g., self-assembly of polyelectrolyte layers) onto the sensor end. The reflection between the thin film and the fiber endface was neglected because of their similar refractive indices. As the film increased its thickness, the length of the fiber cavity changed. The amount of change was estimated by the phase shift of the interferogram. The device could also be used as an immunosensor in which the optical thickness changes were used to... 

Other CVD Processes. CVD also finds extensive use in the production of protective coatings (44,45) and in the manufacture of optical fibers (46-48). Whereas the important question in the deposition of protective coatings is analogous to that in microelectronics (i.e., the deposition of a coherent, uniform film), the fabrication of optical fibers by CVD is fundamentally different. This process involves gas-phase nucleation and transport of the aerosol particles to the fiber surface by thermophoresis (49, 50). Heating the deposited particle layer consolidates it into the fiber structure. Often, a thermal plasma is used to enhance the thermophoretic transport of the particles to the fiber walls (48, 51). The gas-phase nucleation is detrimental to other CVD processes in which thin, uniform solid films are desired. 

In 1987 he was promoted to distinguished member of the technical staff and technical manager. His efforts broadened to include projects on polymer-surface interactions adhesion promotion corrosion protection chemical vapor deposition and thin film growth optical fiber coating synthesis, structure, and reactivity of model organic surfaces and time-resolved surface vibrational spectroscopy. 

Abstract. Structural properties of rubrene thin films on cleaved mica (001) surfaces were investigated by optical microscopy and x-ray diffraction. Optical microscopy shows, that the crystallization of rubrene results in formation of spherulites. X-ray specular diffraction reveals polycrystalline and polymorphic nature of rubrene. The pole figure measurements of films prepared at low deposition rates reveal orthorhombic structure and indicate fiber textures with crystallographic planes (121), (131) and (141) preferentially oriented parallel to the substrate surface. High deposition rate thin films in addition show polymorphism, corroborating the existence of the orthorhombic and the triclinic phase. 

Besides cell designs that employ metals or other electrode materials in disc shape for external reflection spectroscopy, Robinson and McCreery have successfully employed cylindrical carbon fibers of 12 pm diameter [58, 59]. The carbon fiber was illuminated with a tunable dye laser. Scattered light was collected with fiber optics and guided to a photomultiplier detector. Because no thin layer arrangement and consequently poor electrochemical cell response were involved, fast experiments on a microsecond time scale were possible. Studies of polyaniline films deposited on platinum discs have been described [60]. 

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