Abstract: A system and method of inspecting an optical fiber junction is provided. The method includes moving an optical fiber having a junction, a recoat portion overlaying the junction and non-recoat portions on opposite sides of the recoat portion through an imaging region imaged by a pair of cameras. The optical fiber is imaged to acquire a plurality of images with the cameras as the optical fiber continuously moves through a distance to capture images of the recoat portion and the non-recoat portions adjacent to the recoat portion. The plurality of acquired images are evaluated for potential imperfections, and an output is provided indicative of detected images having potential imperfections.

Abstract: Methods of measuring the refractive index profile of a transparent cylindrical object, such as a fiber preform, are disclosed. The methods include transmitting light rays through the cylindrical object in a direction transverse to the central axis at different heights and measuring the deflection angles to define a measured deflection function ?m. The methods include numerically fitting a target deflection function ?t to the measured deflection function ?m within a first object region that does not include the object's outer edge. The fit is conducted by varying the yet unknown parameters of the refractive index profile that define the target deflection function to obtain an estimated refractive index profile ?*i(r) over a second object region equal to or greater in size than the first object region. For cylindrical objects having at least one refractive index continuity, the method is applied to the different regions defined by the at least one discontinuity.

Abstract: According to one embodiment, a method for characterizing a multimode, bend resistant optical fiber may include determining a core refractive index profile for a core portion of a preform and determining a moat refractive index profile for a moat portion of the preform. Thereafter, a property of a multimode optical fiber is determined prior to drawing the multimode optical fiber from the preform. The property of the multimode fiber is determined based on the core refractive index profile of the preform, the moat refractive index profile of the preform, the inner radius rin and the outer radius rout of a depressed-index annular portion of the multimode optical fiber and fiber property coefficients.

Abstract: Methods of measuring the refractive index profile of a transparent cylindrical object, such as a fiber preform, are disclosed. The methods include transmitting light rays through the cylindrical object in a direction transverse to the central axis at different heights and measuring the deflection angles to define a measured deflection function ?m. The methods include numerically fitting a target deflection function ?t to the measured deflection function ?m within a first object region that does not include the object's outer edge. The fit is conducted by varying the yet unknown parameters of the refractive index profile that define the target deflection function to obtain an estimated refractive index profile ?*i(r) over a second object region equal to or greater in size than the first object region. For cylindrical objects having at least one refractive index continuity, the method is applied to the different regions defined by the at least one discontinuity.