An interferometer measuring device is disclosed which includes a workpiece stage (10), a laser interferometer (20) and a measuring reflector (30) mounted on the workpiece stage. The measuring reflector (30) is comprised of a plurality of planar mirrors (31) that are joined together along a horizontal direction. The laser interferometer (20) includes a first interferometer (21) and a second interferometer (22). The first interferometer (21) and the second interferometer (22) are configured such that during a horizontal movement of the workpiece stage (10) with respect to the laser interferometer (20), when light beams emanated from the first interferometer (21) and the second interferometer (22) are incident on a transition section (32) defined by corresponding adjacent two of the planar mirrors (31), the light beam emanated from the first interferometer (21) is incident on one of the adjacent two planar mirrors (31) and the light beam emanated from the second interferometer (22) is incident on the other of the adjacent two planar mirrors (31). Additionally, the first interferometer (21) and the second interferometer (22) alternately provide positional information to the workpiece stage (10). A method for controlling such an interferometer measuring device is also disclosed. The interferometer measuring device and the method enable an extended horizontal measurement range for the workpiece stage (10) by using the plurality of planar mirrors (31) that are joined together as well as by alternating zero-reference updating of the two interferometers (21, 22).

An interferometer measuring device is disclosed which includes a workpiece stage (10), a laser interferometer (20) and a measuring reflector (30) mounted on the workpiece stage. The measuring reflector (30) is comprised of a plurality of planar mirrors (31) that are joined together along a horizontal direction. The laser interferometer (20) includes a first interferometer (21) and a second interferometer (22). The first interferometer (21) and the second interferometer (22) are configured such that during a horizontal movement of the workpiece stage (10) with respect to the laser interferometer (20), when light beams emanated from the first interferometer (21) and the second interferometer (22) are incident on a transition section (32) defined by corresponding adjacent two of the planar mirrors (31), the light beam emanated from the first interferometer (21) is incident on one of the adjacent two planar mirrors (31) and the light beam emanated from the second interferometer (22) is incident on the other of the adjacent two planar mirrors (31). Additionally, the first interferometer (21) and the second interferometer (22) alternately provide positional information to the workpiece stage (10). A method for controlling such an interferometer measuring device is also disclosed. The interferometer measuring device and the method enable an extended horizontal measurement range for the workpiece stage (10) by using the plurality of planar mirrors (31) that are joined together as well as by alternating zero-reference updating of the two interferometers (21, 22).

Generally, in accordance with the various illustrative embodiments disclosed herein, a homodyne optical interferometer can include a multi-phase beam combining system that receives a composite beam from an optical beam guidance system and uses a diffraction grating to produce a diffracted plurality of light beam members. Each of the diffracted plurality of light beam members is propagated through a birefringent optical element that imposes a differential phase shift on each member based on polarization and differing optical path lengths. In one example implementation, the birefringent optical element can be a parallel plate optical element arranged at an angle with respect to a light-propagation axis of the multi-phase beam combining system and in a second example implementation, the birefringent optical element can be a multifaceted optical element having a first planar external surface that is sloped with respect to an opposing external planar surface.

The present invention provides a detection device and a detection method. The detection device comprises a light source module, a receiving module, an image generation module and a judgment module. The light source module is configured to emit light towards a film at a predetermined angle, the receiving module is configured to receive interference light formed by first reflected light reflected by an upper surface of the film and second reflected light reflected by a lower surface of the film, the image generation module is configured to generate an equal thickness interference fringe image according to the interference light, and the judgment module is configured to judge whether thickness of the film is uniform according to the equal thickness interference fringe image. The detection device can perform high accuracy detection on uniformity of the thickness of a film, thereby facilitating improving display quality of a display panel.

An interferometer is provided that includes a single retroreflector arranged at a target plane and a plurality of retroreflectors arranged at a reference plane of the interferometer. The single retroreflector and the plurality of retroreflectors are positioned such that a measurement beam provided to the interferometer makes a plurality of passes between the single retroreflector and the plurality of retroreflectors. One of the plurality of retroreflectors is positioned as a terminal retroreflector that reflects the measurement beam back on itself such that an output of the interferometer is coaxial with an input to the interferometer.

A method for defect inspection of a transparent substrate comprises (a) providing an optical system for performing a diffraction process of object wave passing through a transparent substrate, (b) interfering and wavefront recording for the diffracted object wave and a reference wave to reconstruct the defect complex images (including amplitude and phase) of the transparent substrate, (c) characteristics analyzing, features classifying and sieving for the defect complex images of the transparent substrate, and (d) creating defect complex images database based-on the defect complex images for comparison and detection of the defect complex images of the transparent substrate.

Metrology apparatus and methods are disclosed. In one arrangement, a substrate is inspected. A source beam of radiation emitted by a radiation source is split into a measurement beam and a reference beam. A first target is illuminated with the measurement beam, the first target being on the substrate. A second target is illuminated with the reference beam, the second target being separated from the substrate. First scattered radiation is collected from the first target and delivered to a detector. Second scattered radiation is collected from the second target and delivered to the detector. The first scattered radiation interferes with the second scattered radiation at the detector. The first target comprises a first pattern. The second target comprises a second pattern, or a pupil plane image of the second pattern. The first pattern is geometrically identical to the second pattern, the first pattern and the second pattern are periodic and a pitch of the first pattern is identical to a pitch of the second pattern, or both.

Measuring systems and methods using the same may be provided. For example, the measuring system including a first reference member located at one of a first target member and a second target member, the first and second target members being configured to make a relative movement with respect to each other and the first reference member having a first length, a second reference member located at the other of the first target member and the second target member and having a second length, and a measuring unit located at a distance from the first reference member and the second reference member, the measuring unit configured to measure a relative location of one of the first reference member and the second reference member with respect to the other may be provided.

Generally, in accordance with the various illustrative embodiments disclosed herein, a homodyne optical interferometer can include a multi-phase beam combining system that receives a composite beam from an optical beam guidance system and uses a diffraction grating to produce a diffracted plurality of light beam members. Each of the diffracted plurality of light beam members is propagated through a birefringent optical element that imposes a differential phase shift on each member based on polarization and differing optical path lengths. In one example implementation, the birefringent optical element can be a parallel plate optical element arranged at an angle with respect to a light-propagation axis of the multi-phase beam combining system and in a second example implementation, the birefringent optical element can be a multifaceted optical element having a first planar external surface that is sloped with respect to an opposing external planar surface.

An optical measurement system measuring optical parameters of an object is provided. The object includes at least two light-transmitting layers. The optical measurement system includes a light source module, an image capture module, and a controller. The light source module emits at least two measurement light beams toward the object. The measurement light beams are respectively incident on the object at different angles. The image capture module receives light spots formed on a sensing surface of the image capture module by at least two first light beams after the measurement light beams are reflected by the object and at least two second light beams after the measurement light beams are refracted and reflected between the object. The controller is electrically connected to the image capture module to obtain positions of the light spots. The controller calculates the optical parameters of the object according to the positions of the light spots.