| 摘要 |
PURPOSE:To simplify arithmetic and to improve measurement accuracy by designating the inclination theta of a reference wave with respect to a measurement wave and allowing to coincide the window both end parts with the boundary of an input flux at every line at the time of window processing prior to Fourier transformation. CONSTITUTION:When a plane wave in a direction Z is made incident on a beam splitter 10, it is bisected, and the going straight light beam is reflected by a subject to be measured 12, becomes the measured light beam, and inputted to an area sensor 18 through the splitter 10 and a lens 16. On the other hand, the turning left light beam is reflected by a tilting reflection mirror 14 to become a reference light beam, and is inputted to the area sensor 18 through the splitter 10 and the lens 16 by tilting by an angle theta. When (n) and D are an integer and a sampling section, respectively, a space frequency f0 (=tantheta/lambda, lambdameans wavelength) decides the relationship between the theta and the D so as to satisfy f0=n/D. In the window processing prior to Fourier transformation, the window both end parts are allowed to coincide with the boundary of the input flux at every line. Thus the arithmetic can be simplified and the measurement accuracy can be improved. |
