Bend radius

About: Bend radius is a research topic. Over the lifetime, 3303 publications have been published within this topic receiving 35415 citations. The topic is also known as: minimum bend radius.

Method and waveguides for changing the direction of longitudinal vibrations

Abstract: A curved ultrasonic waveguide, as used in an ultrasonic surgical instrument, comprises two curved half-wave sections, having similar vibratory motion at their respective distal tips, which are integrally or compressively joined at the distal tips to create a single waveguide with a sharper bend radius than is conventionally possible. The resulting waveguide does not produce parasitic motion or generate excessive heat at the input or output portions of the waveguide.

Fiber optic cables that kink with small bend radii

Abstract: Fiber optic cables are disclosed that allow a relatively small bend radius and/or may kink while still preserving optical performance. In one embodiment, the fiber optic cable includes at least one optical fiber, a first strength member, a second strength member, a core material, and a cable jacket. The core material generally surrounds the optical fiber, the first strength member, and the second strength member and the core material is deformable for cushioning the optical fiber. The cable jacket generally surrounds the core material and allows a bending radius of about 10 millimeters or less while maintaining a suitable level of optical performance.

Bend loss measurements on high numerical aperture single-mode fibers as a function of wavelength and bend radius

Abstract: The results of an investigation into the bend loss as a function of wavelength for single-radius bends in monomode fibers are given. The fibers considered have a high numerical aperture and a protective coating which has a refractive index greater than that of the cladding. For these fibers the pure bend loss is shown to be the dominant loss mechanism over the wavelength range 633-1152 nm. In addition, oscillations in the loss are observed as the bend radius is varied at the longer wavelengths. These oscillations are shown to result from the coupling of light under weak coupling conditions from a whispering gallery mode in the cladding formed by the pure bend loss, to the fundamental mode in the core. An expression is derived which relates the bend radius at which the minima in the oscillations occur to the fiber parameters and a qualitative explanation is given for the reduction in the oscillation amplitude as the bend radius and wavelength are decreased. A criterion is identified for assessing the strength of the coupling between the whispering gallery mode and fundamental mode. Using this criterion the attenuation coefficient of the pure bend loss at which a transition from weak to strong coupling occurs is determined and is found to agree with observations. The effect of the coupling strength between the whispering gallery mode and the fundamental mode on the characteristics of the pure bend loss is discussed. Finally, possible applications arising from the results of this work are identified.

Low loss etchless silicon photonic waveguides

Abstract: We demonstrate low loss silicon waveguides fabricated without silicon etching by selective oxidation. We show propagation losses of 0.3dB/cm (λ=1.55µm), roughness of 0.3nm RMS, and 0.0002dB loss for a 90° bend with 20µm bending radius.

Fiber optic interconnection combination closure

Abstract: A fiber optic interconnection combination closure is provided for fashioning optical fiber connections in an enclosed chamber protected from environmental conditions and fiber stress. Fiber splices are fashioned in splice organizers within a closure base assembly. Fiber terminations are fashioned at termination adapters arrayed in a closure chassis. Bend limits for optical fiber are maintained as the fiber is directed on paths in the closure to/from splice organizers, termination adapters, and closure exit portals. Fiber is organized, strain relieved and collected by fiber clips, rings, retainers, and looms positioned such that directed fiber is maintain at a minimum bend radius on such fiber paths. Provided slack storage facilities allow fiber connections to be handled individually without disturbing other connections and/or fibers. Fibers are retained, organized and guided in a path on the closure exterior by attached wire brackets. In this manner, optical signal degradation and/or total loss is avoided by limiting the bending of routed optical fiber to radii in excess of a predetermined minimum bend radius.