CS265491B1 - Method of object's cross position determination - Google Patents

Abstract

The solution allows determining the transverse position of the object with the accuracy of the order of magnitude with relative stability accuracy quantum sources of optical radiation. On the the measured object whose edge is oriented in a direction perpendicular to the wave distribution direction the length of the polychromatic radiation is maintained wavelength polychromatic radiation monotonically distributed in the input width direction slot. The rest of the radiation after the transition it is introduced into the double-barrel through the inlet slot interferometer with constant differential shoulder lengths. Induced interference phase interference shapes object. Method of determining the transverse position object can find application in spectroscopy metrology and optical processing information.

Description

The invention relates to a method for determining the transverse position of an object suitable, in particular, for determining changes in its displacements that are comparable to the wavelength of optical radiation.

Hitherto known methods for determining the transverse position of an object include a method using a parallel beam of white or monochromatic light obtained from a point optical source using a collimator and measuring the radiation intensity behind the object using a measuring slit with a photodetector sliding in the object positioning direction and read at the moment of the minimum signal from the photodetector output. A disadvantage of this transverse position measurement method is the low speed. due to the gradual mechanical displacement of the input slit with the photodetector as well as the low accuracy of the transverse position determination due to the difficulty in controlling the displacement of the entrance slit and the blur of the object shadow due to the final dimension of the white or monochromatic light source. Another known method utilizes a parallel beam of white or monochromatic light obtained from a point optical source by means of a collimator, and the luminous flux of the optical radiation behind the object through a linear permeability mask is measured using a lower lens and a photodetector. The transverse position of the object is determined based on the ratio of the signal values from the mask photodetector to be2 mask. Its disadvantage is the low accuracy due to the blur of the object shadow and also the difficulty of producing an accurate mask with the required linear course of the optical transmittance. Also known is a method of determining the transverse position of an object by means of a video camera, which senses the course of the intensity of the optical shadow cast by the measured object located between the optical radiation source with the optical system and the video camera. The transverse position of the object is determined on the basis of a mutually defined position of the intensity of the optical shadow and its electronically produced mirror image. Its disadvantage is the necessity of mechanical movement of the object relative to the video camera in order to obtain a defined position of the intensity of the optical shadow and its electronically produced mirror image.

The above-mentioned drawbacks are substantially eliminated by the method of determining the transverse position of an object according to the invention, which consists in that the measured object whose measured edge is oriented perpendicularly to the direction of distribution of the wavelengths of polychromatic radiation is conducted monotonically distributed polychromatic radiation. in the direction of the width of the entrance slot, the remaining part of the radiation after passing through the slot is introduced into a two-beam interferometer with a constant arm length difference, where the induced phase difference of the interference patterns indicates the transverse position of the object.

The main advantage of this method of determining the transverse position of an object is an accuracy that is of the order of magnitude comparable to the relative accuracy of the wavelength stability of quantum optical radiation sources. The measurement is independent of the angular dimension of the optical radiation source, i.e. the sharp shadow of the object to be measured in the plane of the inlet slot is not a necessary condition for accurate transverse position determination. The measurement does not require a precisely defined distance between the measured object and the plane of the input slot.

Example

The object to be measured is positioned between the source of polychromatic radiation and the inlet slit so that a portion of the polychromatic radiation whose wavelengths are monotonically distributed in the direction of the width of the inlet slit passing through the inlet slit is the measured edge of the object perpendicular to the direction of distribution. The remainder of the radiation whose spectral composition of the wavelength of the wavelengths is defined by the transverse position of the measured object with respect to the input slit is, after passing through the input slit, introduced into a two-beam interferometer with constant arm length difference stabilized by a quantum standard source of optical radiation. the input slot proportional to the change in the transverse position of the measured object.

The invention can find application in spectroscopy, metrology and optical processing of information.

Claims (1)

OBJECT OF THE INVENTION Method of determining the transverse position of an object by means of an infermeter with constant arm-length difference, characterized in that polyohromatic radiation with a wavelength of monotonous width in the direction of the polychromatic radiation is directed to the measured object whose edge is oriented perpendicular to the direction of distribution of polychromatic radiation wavelengths the slits and the remainder of the radiation after passing through the inlet slit are introduced into a two-beam interferometer with a constant arm length difference, where the induced phase difference phase induced indicates the transverse position of the object.