An optical pressure sensor is disclosed having a pressure sensing optical cavity. A temperature sensing optical cavity at the sensing head is used by an interrogator to correct a pressure signal for effects of temperature. The optical cavities may be, for example, Fabry Perot cavities in the sensor head.

A sensor network having a series arrangement of fiber-coupled, reflective sensors is disclosed. In operation, a first light signal having multiple wavelength bands is launched in an upstream direction on a fiber bus. Each sensor includes a wavelength filter and an FP sensor that is sensitive to a parameter. Each wavelength filter (1) selectively passes a different one of the wavelength bands to its FP sensor and (2) reflects the remaining wavelength bands back into the fiber bus to continue upstream. The FP sensor imprints a signal based on the parameter onto its received light and reflects it as a second light signal. The collimator, wavelength filter, and FP sensor of each sensor are arranged such that each second light signal is returned to the fiber bus, which conveys them in a downstream direction to a processor that measures them and estimates the parameter at each sensor.

An optical system having an optical sensor with an ultra-short FP cavity, and a low-resolution optical interrogation system coupled to the optical sensor and operational to send light signals and receive light signals to and from the optical sensor is disclosed. The optical system may operate in a wavelength range including the visible and near-infrared range. Methods of interrogating optical sensors are provided, as are numerous other aspects.

A fire or overheat detection device includes a diaphragm adjacent to a chamber with a gas inside the chamber, wherein the diaphragm contacts the gas. The fire or overheat detection system also includes a Fabry-Perot interferometer. At least a portion of the Fabry-Perot interferometer is coupled to the diaphragm via a linkage. A light source is configured to direct an input light into the Fabry-Perot interferometer.

An optical sensor (10) comprises an optical cavity defined by a dielectric body and responsive to one or more physical environmental conditions, and a waveguide (70) having a terminal end spaced apart from the optical cavity such that light is optically coupled from the terminal end of the waveguide (70) to the optical cavity. The waveguide (70) is arranged such that, in use, it is maintained at a first temperature that would not damage the optical coupling to the optical cavity when the dielectric body is maintained at a second temperature sufficient to damage the optical coupling to the optical cavity.

An optical pressure sensor is disclosed having a pressure sensing optical cavity. A temperature sensing optical cavity at the sensing head is used by an interrogator to correct a pressure signal for effects of temperature. The optical cavities may be, for example, Fabry Perot cavities in the sensor head.

There is described an optical pressure sensor comprising a sensor housing and an optical pressure cell mounted within the sensor housing and dividing the sensor housing into a first fluid space and a second fluid space. The optical pressure cell comprises a front side exposed to a pressure in the first fluid space and a back side exposed to a pressure in the second fluid space. The optical pressure sensor further comprises a fluid communication arrangement allowing pressure equalization between the pressure in the first fluid space on the front side and the pressure in the second fluid space on the back side of the optical pressure cell.

An intravascular rotary blood pump possesses a catheter (10), a pumping device (50) disposed distally of the catheter and having at its distal end a flexible flow cannula (53) through which blood is either sucked or discharged by the pumping device (50) during operation of the blood pump, and at least one pressure sensor (27, 28A, 30) having at least one optical fiber (28A) which is laid along the flow cannula (53). The optical fiber (28A) and, where applicable, a sliding tube (27) in which the optical fiber (28A) is laid extend along a neutral fiber of the flow cannula (53).

An optical pressure sensor is disclosed having a pressure sensing optical cavity. A temperature sensing optical cavity at the sensor head is used by an interrogator to correct a pressure signal for effects of temperature. The optical cavities may be, for example, Fabry Perot cavities in the sensor head.

A method of assembling an optical sensor for measuring pressure and/or temperature is disclosed. The optical sensor is adapted for use in high temperature environments, such as gas turbines and other engines. The method comprises fabricating a sensor element formed of a pill having an enclosed cavity, bonding the pill to a front end of a spacer, bonding a lens to the back end of the spacer to form the optical assembly, aligning an optical fibre to the optical assembly, and fixing the fibre in position by fusing the fibre to the lens.