Abstract: The movement of a body (1) is determined by mounting on or in the body one or more sources (3,4) and one or more detectors (12,14) such that each source propagates polychromatic light along a path to a detector. Radiation modulation means (19;25) is supported by the body such that a change in the movement of the body causes a displacement of the radiation modulation means in at least one light path to vary the distributed spectral content of the light reaching the detector. The or each detector is adapted to detect the intensity of incident radiation at a plurality of different wavelengths, and analysis means (18) interprets the output of each detector in terms of the movement of the body.

Abstract: A simple and inexpensive optical fibre joint comprises an elongate core consisting of an assembly of rods defining between their adjacent radially outer surfaces a plurality of interstices; an elastomeric sleeve tightly surrounding the core; and two optical fibres aligned in one of the interstices with their neighboring end faces abutting or closely spaced apart. The depth of the interstice and the degree of expansion of the elastomeric sleeve having regard to the diameters of the aligned optical fibres are such that the optical fibres are tightly held in the interstice. The rods constituting the elongate core may be of rigid material or of an elastomeric material.

Abstract: In an optical fiber connector component including a tubular housing and three round rods supported longitudinally side by side within the tubular housing and defining between them an intersticial space for reception of an optical fibre or optical fibres, the tubular housing is of a material having a greater coefficient of thermal expansion than that of the material of the rods. In use, prior to introducing optical fibre into the intersticial space, the tubular housing is heated to cause it to expand radially outwardly to permit radial separation of the rods and introduction of the optical fibre into the intersticial space. The tubular housing is then cooled or permitted to cool to cause the housing to contract radially inwardly to compress the rods inwardly and cause them to grip the optical fiber so that it is aligned axially in the intersticial space.

Abstract: A joint between two optical fibres comprises two cylindrical rods positioned with their longitudinal axes substantially parallel on a support device of such a form that the cylindrical rods are constrained to lie in tangential contact with one another to define between them an interstitial space, the two rods and the support device forming a sub-assembly; two optical fibres aligned in the interstitial space defined by the two rods so that the end faces of the optical fibres substantially abut; an elongate holding member positioned over the ends of the optical fibres aligned in the interstitial space to cover the interstitial space over at least a part of its length; and over the elongate holding member there is applied at least one resilient spring clip which so engages the sub-assembly that the elongate holding member is urged towards the two rods to secure the optical fibres with their end faces substantially abutting in the interstitital space between the two rods.