An interferometry system includes a plurality of coherent light sources that each generate a beam of coherent light. Separate waveguide pathways are optically associated with each coherent light source. Each separate waveguide pathway has an endpoint configured to emit at least a portion of the beam of coherent light from the associated light source. A plurality of photodetectors is optically associated with waveguide pathways. In some cases, a retroreflector receives the light emitted from the endpoints, modulates the received light, and directs the modulated light back to the endpoints. The modulated light and a portion of the coherent light reflected from the endpoint of the waveguide pathway receiving the modulated light is directed a photodetector.

Deriving data for calibration or improving the positioning of a computer-controlled machine including a movable carrier for changing the position of a first machine part relative that of second machine part. The carrier is moved to a plurality of carrier positions such that the position of the first machine part relative to that of the second machine part changes for each of said plurality of positions. At each carrier position, a pattern generator attached to the first machine part is illuminated with at least two illuminators such that at least one spatial light pattern is created in space. Position data related to the position of said carrier is recorded and composite images of said at least one spatial light pattern is recorded in at least two different optical configurations of said at least two illuminators, said pattern generator, and at least one camera.

Processing systems and methods used in the manufacturing of flat panel displays (FPDs) are provided herein. In one embodiment, a processing system features a motion stage movably disposed on a base surface, one or more X-position interferometers, and a plurality of Y-position interferometers. The X-position interferometers include an X-position mirror fixedly coupled to the motion stage and an X-axis stationary module fixedly coupled a non-moving surface of processing system. Each of the plurality of Y-position interferometers include one of a first or second Y-position mirror fixedly coupled to the motion stage in orthogonal relationship to the one or more X-position mirrors and one of a first or a second Y-axis stationary module fixedly coupled to a non-moving surface of the processing system. Here, each of the Y-axis stationary modules is positioned to direct coherent radiation towards a respective Y-position mirror when the Y-position interferometer thereof is in an active arrangement.

In one general aspect, an apparatus can include a first laser subsystem configured to transmit a first laser beam at a first location on an object at a time and a second laser subsystem configured to transmit a second laser beam at a second location on the object at the time. The apparatus can include an analyzer configured to calculate a first velocity based on a first reflected laser beam reflected from the object in response to the first laser beam. The analyzer can be configured to calculate a second velocity based on a second reflected laser beam reflected from the object in response to the second laser beam. The first location can be targeted by the first laser subsystem and the second location can be targeted by the second laser subsystem such that the first velocity is substantially the same as the second velocity.

In one general aspect, an apparatus can include a first laser subsystem configured to transmit a first laser beam at a first location on an object at a time and a second laser subsystem configured to transmit a second laser beam at a second location on the object at the time. The apparatus can include an analyzer configured to calculate a first velocity based on a first reflected laser beam reflected from the object in response to the first laser beam. The analyzer can be configured to calculate a second velocity based on a second reflected laser beam reflected from the object in response to the second laser beam. The first location can be targeted by the first laser subsystem and the second location can be targeted by the second laser subsystem such that the first velocity is substantially the same as the second velocity.

The present disclosure provides an optical coherence tomography (OCT) system for characterising first and second areas of interest of a material. The OCT system comprises first and second optical elements in use positioned at the first and second areas of interest of the material. The first and second optical elements are at least partially transmissive for electromagnetic radiation. The system further comprises first and second scanning heads in use positioned at the first and second optical elements, respectively, to receive electromagnetic radiation that has interacted with the material at the first and second areas of interest. In addition, the system comprises at least one detector optically coupled to the first and second scanning heads. The first and second optical elements are arranged such that respective reference radiation associated with the first and second optical elements is generated by reflection at interfaces of or at the first and second optical elements, respectively, and the first and second optical elements are arranged or positioned such that an optical path length difference between the reference radiation associated with the first optical element reference radiation and electromagnetic radiation that interacted with the material associated with the first optical element differs from an optical path length difference between the reference radiation associated with the second optical element and electromagnetic radiation that interacted with the material associated with the second optical element.

A displacement detecting device includes a first diffraction grating, a light source, a displacement detecting unit, and a light receiving unit. The displacement detecting unit includes a light flux dividing unit, a second diffraction grating, and a reference reflecting member. An incident angle of a first light flux to the first diffraction grating, a diffraction angle of the first diffraction grating, an incident angle of the first light flux to the second diffraction grating, and a diffraction angle of the second diffraction grating are angles at which a displacement amount in an optical path length of the first light flux from the light flux dividing unit to the first diffraction grating and a displacement amount in an optical path length of the first light flux from the first diffraction grating to the second diffraction grating become equal in a case where a measured member is displaced in a direction orthogonal to a measured surface.

A laser interferometer system includes a beam splitter to split a laser beam into first and second beam sets, a first retroreflector mounted to an object to reflect the first beam set, a first detecting device for detecting movements of the object in x-, y- and z-axis directions based on the reflected first beam set, a second retroreflector mounted to the object to reflect the second beam set, and a second detecting device for detecting rotations and movements of the object with respect to the y- and z-axis directions based on the reflected second beam set. The movements of the object in the z-axis direction obtained by the first and second detecting devices are used to obtain a rotation of the object with respect to the x-axis direction.

A sensor for a vibration imaging system is provided. The sensor includes a transmitter configured to project an array of laser beams onto a surface of an object such that neighboring beams in the array of laser beams are frequency shifted relative to each other, an interferometer configured to mix radiations reflected from neighboring points on the surface of the object such that the radiations from neighboring points interfere with one another, a photodetector array configured to produce output signals representative of the interfering beams, a demodulator configured to demodulate the output signals, and a computing device configured to calculate a deformation profile for the object based on the demodulated output signals.

An interferometric position sensor for sensing the position of an object is disclosed. The position sensor comprises a light source arranged to emit light, a beam splitter, and a detector array. The beam splitter is arranged to split the light between first and second optical paths, which are configured such that the split light is recombined so as to form an optical interference pattern dependent on the difference between the optical path lengths of the first and second optical paths. The detector array is arranged to measure the intensity of at least a part of the optical interference pattern. At least one of the first and second optical path lengths is arranged to be dependent on the position of the object, such that changes in the optical interference pattern can be related to changes in the position of the object.