Abstract: A film thickness measuring apparatus capable of restricting a measurement area on the surface of a sample is provided. An incident optical system provides an irradiating polarized light to the surface of the sample. A detecting optical system receives the reflected light having an elliptical polarization and provides a reduced aperture that can restrict the light provided through a fiber optic conduit to a spectrometer and thereby eliminate aberrations and noise problems.

Abstract: A spectral ellipsometer includes a light incident optical system for focusing a incidence spot of polarized light of multi-wavelengths onto a sample surface. A detecting optical system receives the reflected light influenced by the sample surface so that the amount of change in an elliptical polarization will be characteristic of the sample surface. A spherical prism polarizer is employed in the light incident optical system having complimentary curved light incident and light exit surfaces to enable the focusing of the incident light so that each of the ray traces of the range of wavelengths are focused at the same position on the sample surface.

Abstract: A film thickness measuring apparatus capable of restricting a measurement area on the surface of a sample is provided. An incident optical system provides an irradiating polarized light to the surface of the sample. A detecting optical system receives the reflected light having an elliptical polarization and provides a reduced aperture that can restrict the light provided through a fiber optic conduit to a spectrometer and thereby eliminate aberrations and noise problems.

Abstract: A spectral ellipsometer includes a light incident optical system for focusing a incidence spot of polarized light of multi-wavelengths onto a sample surface. A detecting optical system receives the reflected light influenced by the sample surface so that the amount of change in an elliptical polarization will be characteristic of the sample surface. A spherical prism polarizer is employed in the light incident optical system having complimentary curved light incident and light exit surfaces to enable the focusing of the incident light so that each of the ray traces of the range of wavelengths are focused at the same position on the sample surface.

Abstract: A photoreceptor having a marking area whose optical reflection property differs from that of a non-marking area is formed in a portion of a surface of an electrically conductive substrate. The average line of a vertical section of the non-marking area cut across the border line with the marking area is M.sub.0 and the average line of a vertical section of the marking area cut across the border line is N.sub.0 and that straight lines touching the average lines M.sub.0 and N.sub.0 at the intersection of M.sub.0 and N.sub.0 are tangent lines M.sub.1 and N.sub.1, respectively, the acute angle .theta. between M.sub.1 and N.sub.1 is within the range of 0.degree..ltoreq..theta..ltoreq.30.degree.. Setting the angle .theta. within this range enables a photoconductive layer of a uniform characteristic to be laminated on the electrically conductive substrate even when the marking area is formed on the surface of the substrate.

Abstract: According to the present invention, a laser and X-rays are adapted to be coaxial to each other by the combination of a mirror and a focusing lens, whereby an X-ray irradiation position and a range thereof on an object to be subjected to the application of X-rays can be surely monitored even though the X-ray irradiation range is small.

Abstract: An apparatus for continuously measuring the concentration of particulates in a sample gas by using an optoacoustic effect. Identical laser rays are directed along two optical paths, and a chopper and an optoacoustic cell are position in the recited order in each of the optical paths. Sample gas containing particulates is introduced into one optoacoustic cell and sample gas from which the particulates have been removed is introduced into the other optoacoustic cell. The respective choppers are driven for producing a chopping action on the respective laser rays at a frequency corresponding to the resonant frequency of the corresponding optoacoustic cells, and the outputs from the cells can be compared for providing an indication of the concentration of the particulates in the sample gas.