FIELD: optical system; measurement equipment.
SUBSTANCE: invention relates to the field of optical measurements and relates to an apparatus for measuring the propagation length of an infrared surface electromagnetic wave (SEW). Device includes a source of monochromatic radiation, a solid-state sample with a guiding wave with a flat face, an element for converting radiation into SEW, adjustable optical delay line, an element of the SEW transformation into a body wave, a photodetector and a measuring device. Element of the radiation transformation in the SEW is made in the form of a cylindrical segment whose axis is perpendicular to the plane of incidence of the radiation, and its convex surface adjoins the face of the sample and has the length of the line of intersection with the plane of incidence less than the propagation length of the SEW. Element of the transformation of SEW into the body wave is identical to the element of the transformation of the radiation of the source in the SEW. Delay line consists of four mirrors oriented perpendicular to the surface of the sample and adjacent to it. One pair of line mirrors is fixed on the track in the plane of incidence, and the second is placed on a moving platform, the movement of which is limited along the axis of symmetry of the line.
EFFECT: technical result consists in increasing the signal-to-noise ratio and reproducibility of the measurement results.
1 cl, 1 dwg
