In the coming years, in vivo biomedical and biomechanical applications will benefit from a wide range of fiber-optic sensor (FOS) turnkey systems for sensing and measuring almost any physical quantity. These systems have four basic components: the light source, the optical fiber (OF), the sensor element, and the light detector. The light source provides the electromagnetic radiation whose energy is transmitted through the OF to the sensor element, in general, under the principle of total internal reflection. The FOS or transducer is the light modulator, i.e., the entity that causes a light property to change (e.g., amplitude or optical power, phase, polarization, and wavelength or optical frequency) under the influence of a certain physical quantity. Thus a physical quantity (e.g., pressure) can change the physical properties of the sensing element, which, in turn, leads to a change in the light properties. The light detector is necessary to read and analyze a light property variation. Since the four light properties can be considered in most circumstances independent parameters, they offer a wide range of solutions to sense several physical quantities.

The intrinsic advantages of optical sensor technology are very appealing for high voltage applications and can become a valuable asset in a new generation of smart grids. In this paper the authors present a review of optical sensors technologies for electrical current metering in high voltage applications. A brief historical overview is given together with a more detailed focus on recent developments. Technologies addressed include all fiber sensors, bulk magneto-optical sensors, piezoelectric transducers, magnetic force sensors and hybrid sensors. The physical principles and main advantages and disadvantages are discussed. Configurations and strategies to overcome common problems, such as interference from external currents and magnetic fields induced linear birefringence and others are discussed. The state-of-the-art is presented including commercial available systems.

Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.

Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.

A multipoint fiber-optic temperature sensor network integrated inside a power transformer for continuous monitoring of hot-spots on windings, cellulose insulations, and oil, is demonstrated and tested. The temperature sensors are based on proprietary encapsulated fiber Bragg grating (FBG) sensors and the optical interrogation unit uses a special designed narrowband high power broadband fiber source. The fiber-optic sensing network is integrated into a 20 MVA, 345/radic3 kV -20 kV power transformer (CORE type) having 12 temperature sensing points, distributed over several physical locations inside the transformer (windings, cellulose insulators, magnetic circuit, and cooling oil entrance and exit).

Optics InfoBase is the Optical Society's online library for flagship journals, partnered and copublished journals, and recent proceedings from OSA conferences.