A submarine communications cable is a cable laid on the sea bed between land-based stations to carry telecommunication signals across stretches of ocean and sea. The first submarine communications cables laid beginning in the 1850s carried telegraphy traffic, establishing the first instant telecommunications links between continents, such as the first transatlantic telegraph cable which became operational on 16 August 1858. Subsequent generations of cables carried telephone traffic, then data communications traffic. Modern cables use optical fibre technology to carry digital data, which includes telephone, Internet and private data traffic.
Sir Charles Kuen Kao was an electrical engineer and physicist who pioneered the development and use of fiber optics in telecommunications. In the 1960s, Kao created various methods to combine glass fibers with lasers in order to transmit digital data, which laid the groundwork for the evolution of the Internet.
A security alarm is a system designed to detect intrusion, such as unauthorized entry, into a building or other areas such as a home or school. Security alarms used in residential, commercial, industrial, and military properties protect against burglary (theft) or property damage, as well as personal protection against intruders. Security alerts in neighborhoods show a connection with diminished robbery. Car alarms likewise help protect vehicles and their contents. Prisons also use security systems for the control of inmates.
A network tap is a system that monitors events on a local network. A tap is typically a dedicated hardware device, which provides a way to access the data flowing across a computer network.
An optical fiber is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss; in addition, fibers are immune to electromagnetic interference, a problem from which metal wires suffer. Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers are also used for a variety of other applications, some of them being fiber optic sensors and fiber lasers.
Distributed temperature sensing systems (DTS) are optoelectronic devices which measure temperatures by means of optical fibres functioning as linear sensors. Temperatures are recorded along the optical sensor cable, thus not at points, but as a continuous profile. A high accuracy of temperature determination is achieved over great distances. Typically the DTS systems can locate the temperature to a spatial resolution of 1 m with accuracy to within ±1°C at a resolution of 0.01°C. Measurement distances of greater than 30 km can be monitored and some specialised systems can provide even tighter spatial resolutions.
Fiber-optic communication is a method of transmitting information from one place to another by sending pulses of infrared light through an optical fiber. The light is a form of carrier wave that is modulated to carry information. Fiber is preferred over electrical cabling when high bandwidth, long distance, or immunity to electromagnetic interference is required. This type of communication can transmit voice, video, and telemetry through local area networks or across long distances.
Fiber tapping uses a network tap method that extracts signal from an optical fiber without breaking the connection. Tapping of optical fiber allows diverting some of the signal being transmitted in the core of the fiber into another fiber or a detector. Fiber to the home (FTTH) systems use beam splitters to allow many users to share one backbone fiber connecting to a central office, cutting the cost of each connection to the home. Test equipment can simply put a bend in the fiber and extract sufficient light to identify a fiber or determine if a signal is present.
Electro-optical sensors are electronic detectors that convert light, or a change in light, into an electronic signal. These sensors are able to detect electromagnetic radiation from the infrared up to the ultraviolet wavelengths. They are used in many industrial and consumer applications, for example:
A fiber-optic sensor is a sensor that uses optical fiber either as the sensing element, or as a means of relaying signals from a remote sensor to the electronics that process the signals. Fibers have many uses in remote sensing. Depending on the application, fiber may be used because of its small size, or because no electrical power is needed at the remote location, or because many sensors can be multiplexed along the length of a fiber by using light wavelength shift for each sensor, or by sensing the time delay as light passes along the fiber through each sensor. Time delay can be determined using a device such as an optical time-domain reflectometer and wavelength shift can be calculated using an instrument implementing optical frequency domain reflectometry.
Kingfisher International Pty Ltd is an Australian manufacturer of fiber optic test and measurement equipment, located in Mulgrave, Victoria.
Paul B. Ruffin, Ph.D. is an American scientist and educator. He is active in the field of applied science during his career as a research physicist conducting exploratory and advanced research and development in Fiber-optic communication, Microelectromechanical systems (MEMS), and Nanotechnology at the U. S. Army Aviation and Missile Research, Development, and Engineering Center (AMRDEC). In July 2003, Ruffin was promoted to the highest rank for a research scientist — Senior Research Scientist (ST) — that anyone could achieve in Government service, making him the first African American to ever attain such status in the Civilian Army workforce.
Xtralis, now part of Honeywell, was a privately held firm. It manufactures smoke detection, gas detection and video surveillance security products for the early detection, visual verification, and prevention of fire and intrusion threats.
Orbital angular momentum (OAM) multiplexing is a physical layer method for multiplexing signals carried on electromagnetic waves using the orbital angular momentum of the electromagnetic waves to distinguish between the different orthogonal signals.
Biswanath Mukherjee is an Indian-American Distinguished Professor of computer science at University of California, Davis and a fellow of IEEE.
Fiber to the office (FTTO) is an alternative cabling concept for local area network (LAN) network office environments. It combines passive elements and active mini-switches to provide end devices with Gigabit Ethernet. FTTO involves centralised optical fibre cabling techniques to create a combined backbone/horizontal channel; this channel is provided from the work areas to the centralised cross-connect or interconnect by allowing the use of pull-through cables or splices in the telecommunications room.
Tong Sun is a Professor of Sensor Engineering and Director of the Research Centre for Photonics and Instrumentation at City, University of London. She was awarded the Royal Academy of Engineering Silver Medal in 2016 and awarded an Order of the British Empire (OBE) in the 2018 Birthday Honours. In 2020 she was elected Fellow of the Royal Academy of Engineering.
A perimeter intrusion detection system (PIDS) is a device or sensor that detects the presence of an intruder attempting to breach the physical perimeter of a property, building, or other secured area. A PIDS is typically deployed as part of an overall security system and is often found in high-security environments such as correctional facilities, airports, military bases, and nuclear plants.
Senstar Corporation develops and manufactures perimeter intrusion detection systems, video management software, security lighting, personal duress systems, and access control software for the physical security and video surveillance industries. Its headquarters are located in Ottawa, Ontario. Senstar products protect facilities around the world, including critical infrastructure sites, military bases, nuclear power plants, airports, personal estates, borders, and correctional facilities.
Luc Thévenaz is a Swiss physicist who specializes in fibre optics. He is a professor of physics at EPFL and the head of the Group for Fibre Optics School of Engineering.
