Waveguides, such as light guides, made entirely of elastomeric material or with indents on an outer surface are disclosed. These improved waveguides can be used in scissors, soft robotics, or displays. For example, the waveguides can be used in a strain sensor, a curvature sensor, or a force sensor. In an instance, the waveguide can be used in a hand prosthetic. Sensors that use the disclosed waveguides and methods of manufacturing waveguides also are disclosed.

A device for testing overall anchorage performance of a basalt fiber reinforced plastic (BFRP) anchor cable includes an anchor cable anchoring system and a data acquisition system. The anchor cable anchoring system includes a test bed, BFRP arranged over the test bed, and a distributed optical fiber bonded to a surface of the BFRP, the test bed being provided with an anchoring section at one end and an outer anchoring section at the other end, the anchoring section anchors one end of the BFRP, and the outer anchoring section anchors the other end of the BFRP. The data acquisition system includes a modem and a grating connected to two ends of the distributed optical fiber in series, and a center hole jack and a dynamometer arranged between the outer anchoring section and an end of the test bed, and the BFRP penetrates the center hole jack and the dynamometer.

To expand a measurement range with regard to SDH-BOTDR.

A BFS1 and a BFS2, which is obtained by inverting the BFS1, are acquired on the basis of a first measurement signal and a first local oscillation signal that is a cosine wave, a BFS3 is acquired on the basis of a second measurement signal and a second local oscillation signal that is a sine wave, and a Brillouin frequency shift waveform is synthesized from the BFS1 to BFS3. In the case where an optical fiber is not strained or in the case where temperature of the optical fiber is not changed, a phase rotation number N, which is a phase difference between a measurement signal and a local oscillation signal, is calculated on the basis of intensity of the measurement signal, and an offset corresponding to the phase rotation number N is given to the synthesized Brillouin frequency shift waveform.

A sensor pressing member to which a sensor is attached such that the sensor is exposed toward a measurement target. The sensor pressing member presses the sensor in a first direction relative to the measurement target to bring the sensor into contact with the measurement target. The sensor pressing member includes an elastic body positioned opposite the measurement target with the sensor in between in the first direction. The elastic body includes a cavity therein.

A device for coupling a sensor to a fiber optic cable including at least one optical fiber, the device may include an activation unit couplable to a known coupling location along the fiber optic cable and configured to: receive an analog sensor output signal from the sensor and change one or more properties of at least one of: one or more optical wave propagating through the at least one optical fiber and the at least one optical fiber, with respect to the analog output signal, while maintaining at least a portion of a spectral content of the analog sensor output signal during at least a portion of time.

A sensor apparatus includes a sensor device (2), for attaching to an outer surface of a compression garment (1), and a controller. The sensor device (2) comprises a first mounting point (70), attached to a first point on the garment (1), and a second mounting point (45), attached to a second point on the garment (1). The sensor device (2) senses displacement between the first (70) and second mounting points (45). The controller processes information representative of the sensed displacement to estimate a pressure exerted by the compression garment (1) on a wearer of the garment (1).

An optical fiber mold device has a first portion that includes a base layer having a longitudinal feature configured to receive an optical fiber. At least one second portion is disposed over the base layer. The second portion has a center wall and front and back end walls. The center wall, the front end wall, and the back end wall form a mold cavity. At least one first hole is disposed in the mold cavity and is configured to allow mold material to enter the mold cavity. At least one second hole in the mold cavity is configured to allow air displaced by the mold material to exit the mold cavity.

The present invention intends to provide an optical fiber cable sensing apparatus capable of measuring longitudinal directional distribution of curvature and torsion, without using a specially structured optical fiber sensor. This apparatus includes means for inputting data of longitudinal directional distribution of distortion (bending loss, polarization variation) measured for each optical fiber accommodated in an optical fiber cable to be measured and data indicating the position of each measurement object optical fiber on a cable cross section, means for calculating curvature vector κ of the optical fiber cable to be measured, at the same spot, based on the distortion (bending loss, polarization variation) of each optical fiber at the spot and the position of the optical fiber on the cable cross section, and means for calculating torsion τ of the optical fiber cable to be measured at the spot from the calculated curvature vector κ.

An optical fiber sensor with high sensitivity and high spatial resolution is described. The optical fiber sensor includes a multicore fiber having cores configured to permit crosstalk between cores. Crosstalk corresponds to transfer of an optical signal from a core to another core and is used as a mechanism for sensing the external environment surrounding the multicore optical fiber. The degree of crosstalk depends on the relative refractive index profile of the cores and surrounding cladding, as well as on the spacing between cores. The external environment surrounding the multicore optical fiber and changes therein influence crosstalk between cores to permit sensing. The relative refractive index profiles of the cores are also configured to provide a group delay difference for optical signals propagating in different cores. The group delay difference facilitates the position of an external perturbation along the length of the multicore optical fiber.

A machine learning system and method are provided for using fiber-optic Distributed Acoustic Sensor (DAS) and Distributed Temperature Sensor (DTS) data to predict pressure along one or more optical fiber cables. DAS and DTS data are used to train a model to predict pressure based on the DAS and DTS data corresponding to optical signals carried on the fiber cable(s). The trained model is then used to process acquired DAS and DTS data corresponding to optical signals carried on the fiber cable(s) to the predict pressure distributed along the cable(s).