An optical line device for use in an optical line system is configured to connect to a second optical line device via a transmit fiber and a receive fiber. The optical line device includes a transmitter connected to the transmit fiber via an output port of the optical line device, wherein the transmitter is configured to transmit a polarization probe signal at a wavelength outside of a band of wavelengths used for traffic-bearing channels in the optical line signal, to a second polarimeter receiver at the second optical line device; and a polarimeter receiver connected to the receive fiber via an input port of the optical line device, wherein the polarimeter receiver is configured to receive a second polarization probe signal from a second transmitter transmitted from the second optical line device and to derive a measurement of SOP on the receive fiber based on the second polarization probe signal.

The present application relates to a device for testing optical properties and a method for testing optical properties using the same. The device of the present application has inexpensive manufacturing and maintenance costs, is capable of testing a wide range of plane directional phase differences, and provides the method for testing optical properties with improved identification efficiency of the phase retardation axis.

A far infrared imaging system includes a first far infrared polarized light generator, a second far infrared polarized light generator, a first receiving device, a second receiving device, and a computer. The first far infrared polarized light generator emits a first far infrared polarized light, and the second far infrared polarized light generator emits a second far infrared polarized light. The first receiving device receives a first far infrared reflected polarized light, and the second receiving device receives a second far infrared reflected polarized light. The computer processes information received by the first receiver and the second receiver. The polarizer of the first far infrared polarized light generator and the second far infrared polarized light generator includes a carbon nanotube structure including a plurality of carbon nanotubes arranged substantially along the same direction.

The disclosure relates to methods of determining a value of a parameter of interest of a patterning process, and of cleaning a signal containing information about the parameter of interest. In one arrangement, first and second detected representations of radiation are obtained. The radiation is provided by redirection of polarized incident radiation by a structure. The first and second detected representations are derived respectively from first and second polarization components of the redirected radiation. An asymmetry in the first detected representation comprises a contribution from the parameter of interest and a contribution from one or more other sources of asymmetry. An asymmetry in the second detected representation comprises a larger contribution from said one or more other sources of asymmetry relative to a contribution from the parameter of interest. A combination of the first and second detected representations is used to determine a value of the parameter of interest.

The embodiments implement polarization-based disturbed earth identification. At least one sensor apparatus comprising a plurality of detector elements receives polarized electromagnetic radiation (EMR) in a first waveband from a scene of an area of a surface of the earth and polarized EMR in a second waveband from the scene, the polarized EMR in the first waveband having a first polarization orientation and the polarized EMR in the second waveband having a second polarization orientation. The sensor apparatus outputs sensor information that quantifies EMR received by each detector element of the plurality of detector elements. A computing device processes the sensor information to generate an image or a classification image of the scene based on an amount of polarized EMR received by each detector element, and presents the image on a display device.

The embodiments implement polarization-based disturbed earth identification. At least one sensor apparatus comprising a plurality of detector elements receives polarized electromagnetic radiation (EMR) in a first waveband from a scene of an area of a surface of the earth and polarized EMR in a second waveband from the scene, the polarized EMR in the first waveband having a first polarization orientation and the polarized EMR in the second waveband having a second polarization orientation. The sensor apparatus outputs sensor information that quantifies EMR received by each detector element of the plurality of detector elements. A computing device processes the sensor information to generate an image or a classification image of the scene based on an amount of polarized EMR received by each detector element, and presents the image on a display device.

The present invention relates to a light line triangulation apparatus with a measurement space for receiving a measurement object, a light projector, adapted to project a light line into the measurement space and/or onto the measurement object, an imager for detecting the light line in the measurement space, wherein the imager comprises imaging pixels arranged in a plurality of columns and rows. The apparatus of the invention is characterized in that the imager comprises multiple identical sets of polarization filters, wherein each set of polarization filters comprises at least two polarization filters with different polarization directions, wherein a respective polarization filter covers one of the columns.

The present invention relates to a light line triangulation apparatus with a measurement space for receiving a measurement object, a light projector, adapted to project a light line into the measurement space and/or onto the measurement object, an imager for detecting the light line in the measurement space, wherein the imager comprises imaging pixels arranged in a plurality of columns and rows. The apparatus of the invention is characterized in that the imager comprises multiple identical sets of polarization filters, wherein each set of polarization filters comprises at least two polarization filters with different polarization directions, wherein a respective polarization filter covers one of the columns.

Ellipsometers and polarimeters and the like having at least one rotating element which is driven by a motor that comprises air bearings.

A collection system of a semiconductor metrology tool includes a chuck to support a target from which an optical beam is reflected and a spectrometer to receive the reflected optical beam. The collection system also includes a plurality of aperture masks arranged in a rotatable sequence about an axis parallel to an optical axis. Each aperture mask of the plurality of aperture masks is rotatable into and out of the reflected optical beam between the chuck and the spectrometer to selectively mask the reflected optical beam.