A system for inspecting a slab of material may include a polarization maintaining single mode optical-fiber, a linearly polarized broadband light-source configured to emit a polarized-light over the optical fiber, a beam-assembly configured to receive the light over the optical fiber and direct the light toward a slab of material; a polarization-rotator for controlling polarization of the light directed to the slab of material from the beam-assembly; a computer-controlled etalon filter configured to receive the light over the optical fiber, filter the light, and direct the light over the optical fiber; and a computer-controlled spectrometer configured to receive the light over the optical fiber after the light has been filtered by the etalon filter and after the light has been reflected from or transmitted through the slab of material and spectrally analyze the light.

A system for inspecting a slab of material may include a polarization maintaining single mode optical-fiber, a linearly polarized broadband light-source configured to emit a polarized-light over the optical fiber, a beam-assembly configured to receive the light over the optical fiber and direct the light toward a slab of material; a polarization-rotator for controlling polarization of the light directed to the slab of material from the beam-assembly; a computer-controlled etalon filter configured to receive the light over the optical fiber, filter the light, and direct the light over the optical fiber; and a computer-controlled spectrometer configured to receive the light over the optical fiber after the light has been filtered by the etalon filter and after the light has been reflected from or transmitted through the slab of material and spectrally analyze the light.

3D surface inspection apparatus and method are disclosed. The apparatus includes, disposed sequentially, an illumination unit, a polarization splitting unit, a multi-beam splitter, a plurality of phase-shift plates, a polarization combiner and a detector. A light beam from the illumination unit is split by the polarization splitting unit into an inspection beam and a reference beam that are polarized in directions perpendicular to each other. The inspection beam is superimposed with the reference beam, and the superimposition is divided by the multi-beam splitter into a plurality of sub-beams each of which then passes through a corresponding phase-shift plate for generating an additional phase difference between an inspection sub-beam and a reference sub-beam contained in the corresponding sub-beam, so that a plurality of interference signals are generated at the detector surface. The additional phase differences created by the plurality of phase-shift plates are different from one another.

This disclosure relates to an OCT apparatus configured to generate to electromagnetic (e.g., optical) signals having two different polarization states. Two or more silicon optical amplifiers (SOAs) can be configured to maintain a respective polarization state in an optical input signal provided from a light source (e.g., a broadband light source). The different polarization states can be combined by an optical combiner (e.g., a polarization maintaining fiber coupler) and provided to drive a reference arm and a sample arm implemented in an OCT system.

Exemplary embodiments relate to providing an optical image measurement apparatus that is capable of acquiring information on birefringence of a sample while suppressing size and cost of the apparatus. In the present disclosure: second measurement light different from first measurement light is generated using a passive optical element that generates light of second polarization state different from first polarization state; a time when the first measurement light is irradiated onto a sample is adjusted at a first time, and a time when the second measurement light is irradiated onto the sample is adjusted at a second time different from the first time.

An interferometric holographic instrument enables the generation of digital data for testing and enabling 2-dimensional and 3-dimensional analysis of live and real-time semiconductor or anisotropic devices and materials. The digitally recorded interferometric data can be displayed, stored or connected to a live data stream for transmission to digital processing devices. A digital electric processor or analyzer connected to the recording device, or live data stream, enables the interferometric data to be utilized to test, develop, and shape semiconductor and anisotropic microelectronic processing, wireless and microwave devices.

A three-dimensional measurement device includes an optical system that: splits an incident light into two lights; radiates one light to a measurement object and the other light to a reference surface; and emits the combined light; a first irradiator that emits a first light that comprises a polarized light of a first wavelength and enters a first element of the optical system; a second irradiator that emits a second light that comprises a polarized light of a second wavelength and enters a second element of the optical system; a first camera that takes an image of the first light emitted from the second element when the first light enters the first element; a second camera that takes an image of the second light emitted from the first element when the second light enters the second element; and an image processor that performs measurement based on the images.

Apparatus, systems, and methods are used for detecting the alignment of a feature on a substrate using a polarization independent interferometer. The apparatus, system, and methods include optical elements that receive light that has diffracted or scattered from a mark on a substrate. The optical elements may split the diffracted light into multiple subbeams of light which are detected by one or more detectors. The diffracted light may be combined optically or during processing after detection. The system may determine alignment and/or overlay based on the received diffracted light having any polarization angle or state.

An optical tomographic imaging apparatus capable of acquiring a two-dimensional or/and three-dimensional tomographic image having higher SNR and quality by cancelling phase change caused by birefringence of a sample in average processing using a predetermined kernel region, and calculating a global phase difference of each pixel in the kernel. The optical tomographic imaging apparatus includes a processing unit configured to: set a predetermined kernel to a B scan image or/and C scan image (volume data) acquired corresponding to a Jones matrix; model the Jones matrix of each pixel in the set predetermined kernel by using one or more unitary matrices to calculate a relative global phase of each pixel; and cancel the calculated relative global phase in each pixel in the predetermined kernel to average each element of the Jones matrix in the predetermined kernel.

The embodiments of the present disclosure relate to a Fabry-Perot cavity, a manufacturing method thereof, an interferometer and a measuring method for wavelength of light. The Fabry-Perot cavity includes two parallel substrates and a liquid crystal layer between the two parallel substrates, and a sealed cavity is defined between the two substrates; wherein the two substrates comprise a first substrate and a second substrate, light could enter through the first substrate and run out from the second substrate via the liquid crystal layer, and a deflection angle of the liquid crystal layer could be changed by applying various voltage between the two substrates.