FIELD: measuring.
SUBSTANCE: invention relates to non-contact methods of surface investigation by means of infrared (IR) and terahertz (THz) radiation. Device for measuring the depth of penetration of the field of infrared surface plasmon polaritons (SPP) into air contains a source of non-absorbed air p-polarized monochromatic radiation, a cylindrical focusing lens, a sample in the form of a convex cylindrical segment with an axial line, oriented perpendicular to the plane of incidence and the radius of curvature is much greater than the radiation wavelength. Arched surface of the sample is capable of guiding the SPP and is limited in the plane of incidence on both sides by rectangular ribs perpendicular to it, and the length of the arc is of the same order as the propagation length of the SPP. Device has an element for converting SPP into a volume wave, a single-pixel photodetector connected to a galvanometer and an opaque flat screen oriented perpendicular to the SPP track with a wedge-shaped edge inserted into the SPP field and separated from the surface of the sample by an adjustable air gap.
EFFECT: increasing the signal-to-noise ratio when performing measurements with this device.
1 cl, 2 dwg
