A method for determining a position of a mirror of an optical system comprises: a) providing at least one parameter from a mechanical model of the mirror, b) interferometrically detecting a temporal change in a distance of a point of a curved mirror effective surface; and c) ascertaining an amplitude and a phase of N eigenmodes from the temporal change in the distance and the at least one parameter to determine the position of the mirror.

A system determines a position of a rotating object in a device and controls the device according to the determined position of the rotating object. The system includes a reflecting region on the rotating object and a light source located in the device. Emitted light is emitted by the light source onto the reflecting region and reflected light is reflected off the rotating object. The reflected light has an intensity. The system also includes a detector that detects the reflected light and measures the intensity of the reflected light. The reflecting region has a feature configured to effect a change in the intensity of the reflected light as the rotating object rotates. The change in the intensity of the reflected light corresponds to a change in a signal associated with a determined position of the rotating object. The device is controlled according to the determined position of the rotating object.

A method for reporting motion information from an electronic device to a remote host device includes: using an optical sensor for sensing the motion information of the electronic device, the optical sensor being configured within the electronic device; and reporting a motion result of the electronic device to the remote host device based on the optical sensor when the electronic device has moved a predetermined distance each time.

A method for reporting motion information from an electronic device to a remote host device includes: using an optical sensor for sensing the motion information of the electronic device, the optical sensor being configured within the electronic device; and reporting a motion result of the electronic device to the remote host device based on the optical sensor when the electronic device has moved a predetermined distance each time.

An apparatus for measuring the vapour pressure of a liquid hydrocarbon sample is disclosed. The apparatus comprises a sealed chamber (25) for receiving the sample. The chamber (25) is at least partially defined by a moveable element (26) such that moving the moveable element (26) alters the volume of the chamber (25). The apparatus comprises a displacement sensor (29) configured to measure a displacement of the movable element (26).

An apparatus for measuring the vapour pressure of a liquid hydrocarbon sample is disclosed. The apparatus comprises a sealed chamber (25) for receiving the sample. The chamber (25) is at least partially defined by a moveable element (26) such that moving the moveable element (26) alters the volume of the chamber (25). The apparatus comprises a displacement sensor (29) configured to measure a displacement of the movable element (26).

In some examples, an optical encoder may consist of a light source that shines light onto a wheel which then reflects the light onto a sensor. Using information encoded in the reflected light, the rotation of the wheel may be determined. In some examples, rotation of the wheel may be determined by detecting an encoding pattern in light reflected from an exterior surface of the wheel. In some examples, the encoding pattern can be a pattern of light and dark stripes. In some examples, a pattern of light stripes can be generated from light reflecting off of reflective portions of the wheel. Some examples of the disclosure relate to using a surface topology for a wheel that can be used to generate an encoding pattern of light and dark stripes in light reflected from the surface of the wheel, even when the surface of the wheel is uniformly reflective.

An apparatus, a system and a method for detecting position of a movable object in a device and using the same for controlling the device. A distance and/or an intensity of emitted light may be measured by using a sensor to emit light and detect light to determine the location of the movable object. The movable element absorbs emitted light from the sensor. The sensor determines and/or measures an intensity of the emitted light from the sensor which is not absorbed by the movable object. The intensity of emitted light is related to the position of the movable object in the device. A microprocessor may determine the position of the movable object based on the intensity of emitted light detected by the sensor. The position of a rotating object on a crankshaft in an engine may be detected.

An optical sensor system, comprising refractory plasmonic elements that can withstand temperatures exceeding 2500 C. in chemically aggressive and harsh environments that impose stress, strain and vibrations. A plasmonic metamaterial or metasurface, engineered to have a specific spectral and angular response, exhibits optical reflection characteristics that are altered by varying physical environmental conditions including but not limited to temperature, surface chemistry or elastic stress, strain and other types of mechanical load. The metamaterial or metasurface comprises a set of ultra-thin structured layers with a total thickness of less than tens of microns that can be deployed onto surfaces of devices operating in harsh environmental conditions. The top interface of the metamaterial or metasurface is illuminated with a light source, either through free space or via an optical fiber, and the reflected signal is detected employing remote detectors.

A photon momentum sensor includes: a reflector plate that includes: a central disk including a mirror; an annular member; a plurality of spring legs interposed between the central disk and the annular member, such that: the spring legs are interleaved; neighboring spring legs are spaced apart; and the spring legs individually are arranged in an Archimedean spiral that provides orthogonal motion of the central disk relative to the plane of the annular member; and a bias plate disposed opposing the reflector plate such that: the central disk of the reflector plate moves orthogonally to a plane of the bias plate in response to reflection of laser light, and the central disk and the bias plate are arranged spaced apart as a capacitive structure.