First, it is judged whether the diamond film is the single-crystal diamond film or the polycrystalline diamond film according to ellipsometric spectrum data and absorption spectrum data, and different calculation methods are selected to obtain the optical constants and the thickness of the diamond film according to spectral data (e.g., the ellipsometric spectrum data and the absorption spectrum data). Additionally, in the single-crystal diamond film, the optical constants and the thickness of the diamond film are obtained through calculation using the Cauchy model. In the polycrystalline diamond film, the spectral region is selected, and the optical constants and the thickness of the diamond film are obtained through calculation according to the oscillator model and the evaluation function MSE.

A gas sensing element that reflects light incoming along an optical path on a sensing face, where the light reflected by the gas sensing element changes depending on a quantity of a specific gas that is in contact with the gas sensing element, and where each of a first optical fiber and a second optical fiber bends the optical path. The gas sensing element, a light source, a photodetector, and a magnetic field applicator are disposed on a same side with respect to a virtual plane that is perpendicular to an incident plane of the incoming light to the sensing face of the gas sensing element and includes a point on the optical path where light goes out from the first optical fiber and a point on the optical path where light enters the second optical fiber.

A gas sensing element that reflects light incoming along an optical path on a sensing face, where the light reflected by the gas sensing element changes depending on a quantity of a specific gas that is in contact with the gas sensing element, and where each of a first optical fiber and a second optical fiber bends the optical path. The gas sensing element, a light source, a photodetector, and a magnetic field applicator are disposed on a same side with respect to a virtual plane that is perpendicular to an incident plane of the incoming light to the sensing face of the gas sensing element and includes a point on the optical path where light goes out from the first optical fiber and a point on the optical path where light enters the second optical fiber.

A quantization range setting unit (31) of an encoder (30) sets a quantization range for each Stokes parameter of a Stokes vector acquired from a Stokes vector calculation unit (20). The quantization range is set for the Stokes parameter indicating intensity, and is then set for the other Stokes parameters. A quantization unit (32) calculates the Stokes parameter indicating intensity as a predetermined quantization bit number, and calculates the quantization bit numbers of the other Stokes parameters on the basis of the predetermined quantization bit number and the quantization ranges set for the respective Stokes parameters. The quantization unit (32) performs a quantization process on the Stokes parameters on the basis of the quantization ranges and the quantization bit numbers, to generate quantized polarization information. A decoder (40) performs inverse quantization compatible with the encoder 30 on the quantized polarization information, and generates the Stokes vectors before quantization. The amount of polarization information data can be reduced.

A quantization range setting unit (31) of an encoder (30) sets a quantization range for each Stokes parameter of a Stokes vector acquired from a Stokes vector calculation unit (20). The quantization range is set for the Stokes parameter indicating intensity, and is then set for the other Stokes parameters. A quantization unit (32) calculates the Stokes parameter indicating intensity as a predetermined quantization bit number, and calculates the quantization bit numbers of the other Stokes parameters on the basis of the predetermined quantization bit number and the quantization ranges set for the respective Stokes parameters. The quantization unit (32) performs a quantization process on the Stokes parameters on the basis of the quantization ranges and the quantization bit numbers, to generate quantized polarization information. A decoder (40) performs inverse quantization compatible with the encoder 30 on the quantized polarization information, and generates the Stokes vectors before quantization. The amount of polarization information data can be reduced.

Metrology is performed on a semiconductor wafer using a system with an apodizer. A spot is formed on the semiconductor wafer with a diameter from 2 nm to 5 nm. The associated beam of light has a wavelength from 400 nm to 800 nm. Small target measurement can be performed at a range of optical wavelengths.

An optical metrology device characterizes a test object using a phase shift interferometer with synchronous time varying optical frequency shifts. A light source generates a beam having a time varying frequency, which is divided into two collinear, orthogonally polarized beams that differ by a first frequency shift. One or more optical cavities receive the beams and produce a pair of reference beams that differ from each other in frequency by the first frequency shift and a pair of test beams with a second frequency shift induced by the one or more optical cavities. The test beams differ from each other by the first frequency shift and differ from the reference beams by the second frequency shift. The first frequency shift has a pre-defined relationship with respect to the second frequency shift to generate interference between a reference beam and test beam that have frequency shift magnitudes with the pre-defined relationship.

An optical metrology device characterizes a test object using a phase shift interferometer with synchronous time varying optical frequency shifts. A light source generates a beam having a time varying frequency, which is divided into two collinear, orthogonally polarized beams that differ by a first frequency shift. One or more optical cavities receive the beams and produce a pair of reference beams that differ from each other in frequency by the first frequency shift and a pair of test beams with a second frequency shift induced by the one or more optical cavities. The test beams differ from each other by the first frequency shift and differ from the reference beams by the second frequency shift. The first frequency shift has a pre-defined relationship with respect to the second frequency shift to generate interference between a reference beam and test beam that have frequency shift magnitudes with the pre-defined relationship.

An evaluation method includes a step of disposing a sensitive color plate between two polarization plates disposed in a crossed Nicols shape, a step of disposing a measurement material that is a transparent material containing a nanowire between any of one polarization plate or the other polarization plate of the polarization plates and the sensitive color plate, a step of making white light incident from a side of one of the disposed polarization plates, a step of observing a color of the measurement material from a side of the other polarization plate, and a step of evaluating an orientation direction of the nanowire from the color of the measurement material obtained by observation.

An evaluation method includes a step of disposing a sensitive color plate between two polarization plates disposed in a crossed Nicols shape, a step of disposing a measurement material that is a transparent material containing a nanowire between any of one polarization plate or the other polarization plate of the polarization plates and the sensitive color plate, a step of making white light incident from a side of one of the disposed polarization plates, a step of observing a color of the measurement material from a side of the other polarization plate, and a step of evaluating an orientation direction of the nanowire from the color of the measurement material obtained by observation.