Search

Calcium aluminate glass has a refractive index less than 1 at 10.6 [[micro]meter], and therefore it is a good candidate for a hollow fiber for the transmission of C[O.sub.2] laser energy. We have drawn hollow calcium aluminate glass fibers with inner diameters ranging from 380 to 500 [[micro]meter]. The loss for our 500-[[micro]meter] inner-diameter hollow glass fibers measured at 10.6 [[micro]meter] is 8.6 dB/m.

Glass-clad optical fibers comprising a crystalline semiconductor core have garnered considerable recent attention for their potential utility as novel waveguides for applications in nonlinear optics, sensing, power delivery, and biomedicine. To date, cladding compositions have relied on commercially-available expedients and have not been tailored for the specific semiconductor core nor the application. In this work, more-optimum silicate and nonoxide glass compositions are developed for unary ( Si, Ge), binary ( InSb, GaAs), and ternary ( GaAlSb) semiconductor cores based on two main design criteria: (1) matching the thermal expansion coefficient between semiconductor core and glass cladding and (2) matching the viscosity-temperature dependences such that the cladding glass draws into fiber at a temperature slightly above the melting point of the semiconductor. While this latter requirement is critical to the molten core fabrication method, which offers a practical approach to long fiber lengths at acceptable manufacturing speeds (>m/s), these compositions are more broadly applicable to other semiconductor fiber processing methods. Preliminary experimental results on silicon core optical fiber are provided and show a marked diminution in oxygen content relative to analogous fibers drawn using a pure silica cladding. [ABSTRACT FROM AUTHOR]

Optical fibers are described that emit visible light along their length when particulate up-converters in the cladding are excited by light from semiconductor light sources propagating in the core and leaking into the cladding. These eye-catching fibers can be made in almost any color. They can enhance the display of safety gear, enliven novelty clothing displays, make more spectacular theatrical costumes and find use in a wide range of specialty fabrics for other novel display applications. [ABSTRACT FROM PUBLISHER]

The authors report laser oscillation in what appears to be a single transverse mode with very large mode area in optical fibers having heavily Nd-doped 100 μm diameter cores with refractive index significantly lower in the core than in the surrounding cladding. Since fibers of this type cannot support conventional index-guided modes, their results appear to confirm a recent analysis which predicts gain-guided single-mode propagation in index antiguided fibers, provided the gain coefficient in the core exceeds a threshold value. Fibers of this type may be of significant interest for amplifiers and oscillators having large power outputs and/or small nonlinear pulse distortion. [ABSTRACT FROM AUTHOR]

Atmospheric-pressure microplasma jets from a linear array of five hollow-core optical fibers are described. All plasma plumes from the array were quite narrow but long enough to apply the direct treatments to a very small object. The optical intensities from five individual plasma jets were also stable and had a good uniformity. The variation of the optical intensities of individual plasma plumes was within 15%. This plurality of the small-sized plasma jets can be utilized to target some groups of different cells simultaneously in an in vitro biomedical application. [ABSTRACT FROM AUTHOR]

A flexible atmospheric pressure microplasma jet device utilizing a 200-\mu \m hollow-core optical fiber was developed in order to trigger the apoptosis of cultured tumor cells and determine the feasibility of plasma endoscopy. As determined by in situ apoptosis assay, the TUNEL assay, this flexible microplasma jet induced cultured murine tumor cells to undergo apoptosis. In addition, the apoptosis was induced to a greater extent in B16F0 tumor cells than in CL.7 cells for the same plasma dose. [ABSTRACT FROM AUTHOR]