A current conduction element includes an electrical, conductor and an insulation of the electrical conductor. The insulation includes a light waveguiding unit. Furthermore, a system and method for insulation monitoring are described.

A shape calculating apparatus includes a light source, an optical fiber provided with detection targets. The detection targets have mutually different light absorption spectra to decrease a quantity of light propagated by the fiber in accordance with a bend shape of the fiber. The apparatus also includes a light detector to detect light quantity information at wavelengths included in the light absorption spectra, a calculator to execute a calculation relating to a shape of each detection target based on the light quantity information. The apparatus further includes a setting change unit to change, with respect to each of the wavelengths, a dynamic range of at least either an intensity of light input to the optical fiber or an electric signal generated by the detector.

A curvature sensor is to be mounted along detection target to allow a curvature of the detection target. The sensor includes a light source, a light guide to guide light from the light source and sensing parts having light absorbability. The sensing parts include absorption bands having different intrinsic absorption patterns and characteristic absorption bands having intrinsic characteristic absorption patterns in the absorption bands. A light detector allows residual light not absorbed by the characteristic absorption bands to be detected, the residual light being included in light of bands corresponding to the characteristic absorption bands and radiated to the sensing parts from the light source. A calculator computes a curvature of the detection target based on a rate of change in the residual light.

Apparatus for measuring deformation of an elongate body defining an axis, the apparatus including: an optical fibre arranged relative to the body, the optical fibre including a first strain sensitive optical fibre portion coupled to the body and at least partially aligned at a first angle relative to the axis, and a second strain sensitive optical fibre portion coupled to the body and at least partially aligned at a second angle relative to the axis, the second angle being opposite to the first angle; a radiation source connected to an end of the optical fibre, the radiation source being for supplying electromagnetic radiation to the optical fibre; a sensor connected to an end of the optical fibre, the sensor being for sensing electromagnetic radiation received from the first and second optical fibre portions; and a processing device for determining the deformation of the body using the sensed electromagnetic radiation, the deformation including any axial or torsional deformation.

What are disclosed are a flexible display device and a method of detecting a curved state of a flexible display panel thereof, which can estimate a curved state of a flexible display panel. The flexible display device includes a flexible display panel and a controller. The flexible display panel includes N optical fibers which can be curved with the curving of the flexible display panel, a laser transmitter disposed at an input terminal of the optical fiber and a light intensity detector disposed at an output terminal of the optical fiber, wherein N is an integer greater than or equal to 1. The controller is configured to acquire a light intensity parameter detected by the light intensity detector, and determine a current state of the flexible display panel according to the light intensity parameter, wherein M is an integer greater than or equal to 1 and smaller than or equal to N.

The application describes methods and apparatus for distributed fiber sensing, especially distributed acoustic/strain sensing. The method involves launching interrogating radiation in to an optical fiber and sampling radiation backscattered from within said fiber at a rate so as to acquire a plurality of samples corresponding to each sensing portion of interest. The plurality of samples are divided into separate processing channels and processed to determine a phase value for that channel. A quality metric is then applied to the processed phase data and the data combined to provide an overall phase value for the sensing portion based on the quality metric. The quality metric may be a measure of the degree of similarity of the processed data from the channels. The interrogating radiation may comprise two relatively narrow pulses separated by a relatively wide gap and the sampling rate may be set such that a plurality of substantially independent diversity samples are acquired.

The present invention relates to a sensing system and a sensing method using the same. The sensing system includes at least one tested unit and an optical fiber measuring unit. The tested unit includes a container, a strain arm and a float. The container can be filled with a fluid, and the strain arm is connected with the float and combined with a measuring portion of the optical fiber measuring unit. When the container is disposed on a body of interest, the surface inclination or settlement of the body of interest would cause changes of buoyant force on the floating element and induce bending deformation of the strain arm. Accordingly, the surface deformation of the body of interest can be determined by detecting the bending deformation of the strain arm using the measuring portion combined with the strain arm.

Systems and methods for detecting strain are disclosed. In some embodiments, a system may include an optical fiber comprising one or more of a first end configured to receive light emitted by a light source, a second end configured to transmit light to a detector, a first fiber section having a first propagation loss parameter, and a second fiber section having a variable propagation loss parameter, the variable propagation loss parameter. In some embodiments, the variable propagation loss parameter may increase as the second fiber section is deformed.

The application describes methods and apparatus for distributed fiber sensing, especially distributed acoustic/strain sensing. The method involves launching at least first and second pulse pairs into an optical fiber, the first and second pulse pairs having the same frequency configuration as one another and being generated such that the phase relationship of the pulses of the first pulse pair has a predetermined relative phase difference to the phase relationship of the pulses of the second pulse pair. In one embodiment there is a frequency difference between the pulses in a pulse pair which is related to the launch rate of the pulse pairs. In another embodiment the phase difference between the pulses in a pair is varied between successive launches. In this way an analytic version of the backscatter interference signal can be generated within the baseband of the sensor.

A insertion/removal apparatus comprises an insertion section with flexibility which is inserted into a target object to perform a desired operation, a shape sensor, an insertion section shape calculator, and a direct manipulation information estimation circuit. The shape sensor detects bending of the insertion section and outputs a detection signal. The insertion section shape calculator which calculates insertion section shape information indicating a shape of the insertion section, based on the detection signal output from the shape sensor. The direct manipulation information estimation circuit which estimates direct manipulation information including at least one of an insertion/removal amount and a rotation amount of the insertion section inserted into and removed from the target object, based on the insertion section shape information.