Abstract: Methods and systems for inspecting a bare optical fiber spool are disclosed. The system inspects the bare optical fiber spool prior to optical fiber winding and determines whether the bare optical fiber spool is acceptable for the winding.

Abstract: A system and technique for determining discontinuities over a span of a multimode optical fiber (MMF). An optical time domain reflectometer (OTDR) has an operating port, and a first end face of a singlemode optical fiber (SMF) is coupled to the operating port. Light pulses produced by the OTDR emerge from a second end face of the SMF, and an alignment stage aligns the second end face with an end face of a multimode optical fiber (MMF) having a core of given radius. The light pulses from the second end face of the SMF are applied at selected radial positions on the MMF core to excite corresponding mode groups in the MMF. Backscatter light produced by each excited mode group is coupled to the OTDR through the SMF. Locations and values of events detected along the MMF are indicated on the OTDR for each selected radial position.

Abstract: A system and technique for determining discontinuities or events over a span of a multimode optical fiber (MMF). An optical time domain reflectometer (OTDR) has an operating port, and a first end face of a singlemode optical fiber (SMF) is coupled to the operating port. Light pulses produced by a source in the OTDR emerge from a second end face of the SMF, and an alignment stage aligns and matches the second end face with an end face of a multimode optical fiber (MMF) having a fiber core of given radius. The light pulses from the second end face of the SMF are applied at selected radial positions on the MMF core to excite corresponding mode groups in the MMF. Backscatter light produced by each excited mode group is coupled to the OTDR through the SMF, and locations and values of events detected along the MMF are indicated on the OTDR for each of the selected radial positions.

Abstract: This disclosure provides a method, system, and computer system for measuring bending loss of an optical fiber with an optical time domain reflectometer (OTDR). Generally, the method of the present invention provides OTDR device that measures a one-way OTDR splice loss at a point in the optical fiber. Subsequently, a bend is introduced into the optical fiber and a second one-way OTDR splice loss measurement is performed at the same point in the optical fiber as the first measurement. Thereafter, the bending loss of the optical fiber is determined and related to an approximate cut-off wavelength of the optical fiber.

Abstract: This disclosure provides a method, system, and computer system for measuring bending loss of an optical fiber with an optical time domain reflectometer (OTDR). Generally, the method of the present invention provides OTDR device that measures a one-way OTDR splice loss at a point in the optical fiber. Subsequently, a bend is introduced into the optical fiber and a second one-way OTDR splice loss measurement is performed at the same point in the optical fiber as the first measurement. Thereafter, the bending loss of the optical fiber is determined and related to an approximate cut-off wavelength of the optical fiber.