Abstract: The present invention provides a strain gauge comprising a resistive layer. The resistive layer comprises metallic or semiconducting nanoparticles or aggregates thereof in which the nanoparticles or aggregates thereof are separated by insulating and/or semiconducting material.

Abstract: The present invention is to a method of adapting optical rare-earth-doped waveguide (10) having a plurality of transverse propagation modes, such that in use, signal gains of non-fundamental modes of the waveguide are attenuated relative to a signal gain of a fundamental mode of the waveguide. The waveguide (10) has a light-guiding region (45) defined by a refractive index-modifying dopant, such as Ge, which has a thermal diffusion coefficient at temperature T in the waveguide greater than a thermal diffusion coefficient of the rare-earth dopant at temperature T. The method comprises heating the waveguide (10) at the temperature T such that a concentration profile of the refractive index-modifying dopant becomes broader than a concentration profile of the rare-earth dopant.

Abstract: In the method of detecting a localized sun gear fault, in the operation of an epicyclic gear train having ring, planet and sun gears, and a planet carrier, the steps that include detecting sun gear vibrations transmitted through each planet gear, computing separated averages of such detected vibrations, phase shifting the averages to account for the differences in gear meshing positions, and re-combining the phase shifted averages to produce a modified average value of the sun gear vibration.

Abstract: An improved optical modulator and photodetector suitable for high frequency operation and compatible with monolithic microwave integrated circuit technology. Typical implementations use a reversed biased diode containing not intentionally doped (NID) optically active region sandwiched between conductive layers of p-doped and n-doped semiconductor layers, respectively. With monochromatic optical radiation incident upon the device a photocurrent (comprising of an electron-hole pair created for each photon absorbed) can be generated using the optical nonlinearity of the multiple quantum well structure inside the active region. This photocurrent can be used in an external circuit to provide photocurrent feedback to the device itself.