A detector of high-energy (higher than 100 eV) ionising radiation, including an optical fibre having an outside diameter, called the fibre diameter, smaller than 250 microns, including a fibre core, a first cladding, called the useful cladding, encircling the fibre core and a second cladding, called the protective cladding, encircling the useful cladding, and a scintillating layer provided to convert the ionising radiation into light; including a portion, called the detecting portion, arranged in a length of the fibre and having a void formed in the protective cladding, in the useful cladding, and possibly in the fibre core, the scintillating layer being arranged in the void in contact with the useful cladding and the fibre core.

A method and device for monitoring a measurement object. A passive unit has a light source, which radiates radiated light modulated by at least one external measurement influence from the measurement object. An active unit has an optical detector, which receives the radiated and modulated light via an optical link. In addition, there is a transmitter unit emitting energy, such as optical energy, sound energy, electromagnetic energy etc. The emitted energy is coded by an energy signature and sent to the passive unit via an energy link. The passive unit receives the emitted energy by a receiver unit, which decodes the energy signature and moderates the radiated and modulated light in dependence of the energy signature. The received energy is also used to drive the light source. A processor unit may decode the signal for discriminating the signal from error sources.

The invention relates to a method for interrogating at least one optical sensor that is provided within or connected to an optical path at a sensor position, the optical path connecting the optical sensor to a near end of the optical path. The at least one optical sensor has a known frequency-dependent course of its reflectivity that is changed by a physical parameter to be sensed, especially the temperature or humidity of the environment surrounding the at least one optical sensor or the pressure being exerted onto the at least one optical sensor. The method includes the steps of: feeding at least two optical probe signals having differing optical center frequencies to the near end of the optical path, where the at least two optical probe signals are time-shifted versus each other in a predetermined manner when being fed to the near end of the optical path, or where a predetermined time shift between the at least two optical probe signals or corresponding optical reflection signals is introduced within the optical path or within an optical receiver using a chromatic dispersion generating component; detecting reflected optical power portions of the at least two probe signals (optical reflection signals) created by the at least one optical sensor depending on its frequency-dependent course of the reflectivity and the optical frequencies of the at least two optical probe signals, assigning each optical reflection signal detected to one of the at least one optical sensor and assigning the correct optical frequency to each optical reflection signal detected using a known round-trip delay of the at least two optical probe signals between the near end and the respective sensor position and/or using the time shift relation between the at least two optical probe signals; and determining an absolute value or a value range or a change of a value or value range of the parameter to be sensed from the presence of one or more of the optical reflection signals or the maximum optical power or the optical energy thereof, from the frequency-dependent course of the reflectivity of the at least one optical sensor and its dependency on the parameter to be sensed, and from the optical frequency of each of the optical reflection signals detected or from one or more dependencies that link these physical conditions.

A distributed measurement system includes a first distributed optical sensing fiber deployed along a first desired measurement path and a second distributed optical sensing fiber deployed along a second desired measurement path. The system further includes an interrogation system coupled to the first distributed optical sensing fiber and to the second distributed optical sensing fiber. The system also includes a first distributed measuring instrument launch a first interrogating probe pulse set comprising a first pulse having a first frequency and a second pulse having a second frequency. The interrogation system is designed to direct the first pulse to the first distributed optical sensing fiber and the second pulse to the second distributed optical sensing fiber.

Optical fiber having a graphene coating, a method to apply a graphene coating onto an optical fiber, and a fiber optic cable having a graphene coating are disclosed. A first carbon based coating is applied to an optical fiber along a longitudinal axis of the optical fiber. A laser beam is focused at the first carbon based coating. A first surface of the first carbon based coating is photothermally converted into a first layer of graphene.

A fiber optic sensor, a manufacturing method thereof and a motion sensing device relating to the field of sensors are provided. The fiber optic sensor includes a bushing, a magnetic mass block and a sensing optical fiber. The magnetic mass block is located in the bushing, and a magnetic fluid is adsorbed onto an outer surface, opposite to an inner wall of the bushing, of the magnetic mass block, such that the magnetic mass block is capable of being suspended in the bushing and moving along an axis of the bushing. One end of the sensing optical fiber is in a first end opening of the bushing. A surface, opposite to the sensing optical fiber, of the magnetic mass block is a reflecting surface. The sensing optical fiber is configured to provide incident light for the reflecting surface and to receive measuring light from the reflecting surface.

A displacement measuring apparatus, a displacement measuring method and a photolithography device are disclosed. The displacement measuring apparatus includes a light source module (300), a diffractive member (200), a reader head assembly (100), an optical detection module (410, 411, 412, 413) and a signal analysis module (500). The reader head assembly (100) is configured to receive two input light beams (610, 611) from the light source module (300) and guide them so that they come into contact in parallel with the diffractive member (200) and are both diffracted. The diffracted input light beams are guided and combined to form at least one output light beam (612, 613, 614) each containing diffracted light signals respectively of the two input light beams (610, 611), which exit in the same direction from the same light spot location of the diffractive member (200). Displacement information of the diffractive member (200) can be derived from phase change information contained in an interference signal produced by each output light beam (612, 613, 614). The displacement measuring apparatus and method can be used to achieve independent displacement measurements in different direction, with adaptivity to a wide angle and reduced nonlinearity errors. The photolithography device includes the displacement measuring apparatus.

A plastic scintillating fiber capable of detecting radiation having a weakly penetrating property is provided. A plastic scintillating fiber according to an aspect of the present invention includes a plastic optical fiber, and further includes a core containing at least one type of a fluorescent agent, a cladding layer having a refractive index lower than that of the core disposed at a center, and an outermost layer covering an outer peripheral surface of the cladding layer. The outermost layer contains a base material that generates scintillation light, and at least one type of a fluorescent agent that converts the scintillation light into light having a wavelength longer than that of the scintillation light.

A system is provided with a measurement system having a light source, a light sensor, and a controller coupled to the light source and the light sensor. The controller is configured to determine a clearance between a rotor and a casing at least partially based on an interruption of light transmitted from the light source to the light sensor.

Examples of a optoelectronic transducer module with integrated signal processing for use in thermographic temperature measurement are disclosed. The module includes a light source, an optical element to couple the light to an optical port, a connector configured to connect the optoelectronic transducer module to a fiber optic sensor, a detector to detect an emitted light from the fiber optic sensor and convert the detected emitted light into an electrical signal and a module processing unit coupled to the light source and the detector configured to convert the electrical signal into a set of digital results. The optoelectronic module is in communication with an external processing unit using a high speed circuitry for data aggregation and a low speed circuitry for configuration and firmware upgrade in the module. The opto-electronic module is replaceable during operation to avoid big downtime.