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 device for measuring strain in an elongated metallic bar, the device comprising a housing arranged to be secured to the metallic bar, at least one optical sensor, at least one light source arranged to emit light across an interior space of the housing, and a thread arranged freely movable within a sheath and having a proximal end extending to a distal end of the housing and a distal free end arranged to be attached to the metallic bar at a distance from the housing such that longitudinal deformation of the metallic bar causes displacement of the proximal end of the thread in relation to the housing, and wherein the at least one optical sensor is configured to measure the displacement of the proximal end of the thread by measuring light emitted from the at least one light source.

A method is provided for spatially modulating electromagnetic radiation at high frequency where the modulation is phase, polarization or direction of propagation comprises a substrate carrying an ordered array of optical elements in relative motion with respect to an incident beam of electromagnetic radiation to be modulated and measuring the relative motion. The array contains at least three optical elements and at least two different types of optical elements. At least some of the optical elements are formed from and integral to the substrate material. The optical elements may be fabricated on the substrate material by a subtractive process. The electromagnetic radiation to be modulated is incident on a region of the substrate termed the active region. As the substrate moves relative to the incident electromagnetic radiation, the active region also moves and the designation of individual optical elements changes also.

The invention pertains to a contactless measurement method for detecting rotation of an object over an axis coinciding with an optical axis of a probe beam. The probe beam is comprised of two monochromatic wavelengths with circular polarizations of opposite chirality, having a frequency difference for providing a heterodyne probe beam. A neutral beam splitter is provided that directs a reflected beam via a polarizer filter towards a first photodetector and that directs a transmitted beam toward a quarter wave plate attached to a rotatable object. A mirror reflects the probe beam, via the same quarter wave plate, back into the neutral beam splitter, which directs the reflected beam via a polarizer filter toward a second photodetector. The rotation is derived from the relative phase difference between the first and second photodetector signals.

The position detector of an object includes a body defining an input receiving an optical fibre delivering a light signal, and an output delivering a signal representative of the position of the object. A mirror is mounted to move between first and second positions in the body with respect to the input. The first position or the second position ensures transmission of the light signal from the input to the output. The other of the first position and the second position prevents transmission of the light signal to the output. A spring is mounted in the body in order to place the mirror in the first position. A tip is movable relative to the body between a first position and a second position along a direction of movement and is intended to cooperate with the object to be monitored.

Example position detection means and displacement detection devices are described. A relative position detection means optically detects a relative position of displacement of an object to be measured in a measuring direction, including a target mounted on the object to be measured and irradiated with light from a light source; a light receiver for detection of relative position for receiving light by changing polarization state of reflected light at the target with respect to the light; and a relative position information output unit for outputting relative position information based on displacement of the target in the measuring direction based on change of polarization state of the reflected light. The target includes a reflector mounted on the object to be measured and a birefringent member on the reflector and having a thickness changing from a tip to a base end along the measuring direction.

A timing apparatus, system, and method are provided to determine a position of a rotating object in a device, such as an engine, and control the device according to the determined position of the rotating object. Light is emitted from a light source onto a reflecting region on a portion of the rotating object. Light is reflected off the reflecting region of the rotating object and detected as the rotating object rotates. Intensity of the reflected light is measured, via a microcontroller, and the position of the rotating object is determined according to the intensity of the detected light. A signal is generated that corresponds to the intensity of the detected light associated with the determined position of the rotating shaft. The reflecting region has a feature configured to effect a change in the intensity of the reflected light as the rotating object rotates. The microcontroller is configured to determine the determined position and to utilize the determined position and the change in the signal to control operating characteristics of the device.

A state visualizer according to one aspect of the present disclosure includes an optical member including a fixed part that has a fixed relative positional relationship with an object to be measured and a movable part that is movably supported by the fixed part and keeps a constant angle with respect to a gravity direction, the optical member retroreflecting a light or an electromagnetic wave in a case where the fixed part and the movable part are in a predetermined positional relationship. The optical member changes an intensity of the light or the electromagnetic wave reflected in a retroreflection direction in accordance with a change of a relative positional relationship between the fixed part and the movable part.

A method is provided for spatially modulating electromagnetic radiation at high frequency where the modulation is phase, polarization or direction of propagation comprises a substrate carrying an ordered array of optical elements in relative motion with respect to an incident beam of electromagnetic radiation to be modulated and measuring the relative motion. The array contains at least three optical elements and at least two different types of optical elements. At least some of the optical elements are formed from and integral to the substrate material. The optical elements may be fabricated on the substrate material by a subtractive process. The electromagnetic radiation to be modulated is incident on a region of the substrate termed the active region. As the substrate moves relative to the incident electromagnetic radiation, the active region also moves and the designation of individual optical elements changes also.

New platform technologies to actuate and sense force propagation in real-time for large sheets of cells are provided. In certain embodiments the platform comprises a device for the measurement of mechanical properties of cells or other moieties, where device comprises a transparent elastic or viscoelastic polymer substrate disposed on a rigid transparent surface; and a plurality of micromirrors disposed on or in said polymer substrate, wherein the reflective surfaces of the micromirrors are oriented substantially parallel to the surface of said polymer substrate. In certain embodiments the device comprises more than about 1,000,000, or more than about 10,000,000 micromirrors. In certain embodiments the micromirrors comprise a magnetic layer and/or a diffraction grating.