Abstract: A method for measuring an optical length of light path based on use of multiple-beam interference of light and carried into effect by forming an original light beam with two collinear components having mutually independent polarizations and different frequencies in such a manner that when forming each of the following interfering light beams from the preceding one, polarizations of the light components having different frequencies are mutually converted, whereupon the interfered light is converted into an electric signal and its phase is measured, by which the light path optical length is determined.

Abstract: A method for sensing a spatial coordinate of a point of an article, wherein a main coherent light field is formed in the area of the article and an approximate coordinate of a selected point of the article is found by means of an optical characteristic of this field. Simultaneously, a system of additional coherent light fields is formed in the area of the article, said light fields having periodic spatial and temporal modulation of illumination, and engaged in no interaction with the main coherent light field and between one another. The phase of each additional coherent light field in the selected point of the article is measured. Making use of the already obtained approximate coordinate of the selected point of the object and the measured phases, increasingly accurate coordinates of the selected point of the article are successively found. An apparatus for realizing the proposed method includes transmitting and receiving sections.

Abstract: A method is based on utilization of interference patterns for determining an increment of a third coordinate with two given coordinates. An interference pattern is produced on a surface under investigation whereupon one of interference bands is marked to obtain a zero reference band. The subsequent step is to determine the attitude of an interference extremum surface corresponding to said reference band. Thereafter the period of all extremums is distributed along the axis of the third coordinate and an increment of the third coordinate is determined relative to the surface of the zero band by adding up values of periods of surfaces corresponding to bands between the zero reference point and two predetermined reference points.A device for accomplishing the hereinproposed method comprises an optical system for producing an interference pattern, a photorecorder to record said pattern, a coordinate setting unit, and a unit for determining the number of the band of the recorded interference pattern.

Abstract: A phase-metering device comprises first and second input signal sources; N-1 phase-shift circuits at N exceeding two, which are placed in series, a phase shift of each of said circuits being equal to .pi./N radians, the input of the first phase-shifter circuit being connected to the second input signal source; N phase converter units each having two potential (positive and inverted) outputs and two pulse outputs, first inputs of said units being connected to the first input signal source, a second input of the first phase converter unit being connected to the first input signal source, while second inputs of the other phase converter units are coupled to the outputs of the respective phase-shift circuits; the outputs of said phase converter units being connected to inputs of a pulse distributor whose outputs are coupled to inputs of a reversible counter; a digital recorder being connected to the outputs of said reversible counter.

Abstract: A device for obtaining a topographic picture of the surface of a rotating object comprising turret assembly mounting a pulsed laser, a photorecorder, an optical system for forming a set of light planes, and a system designed to synchronize a laser emission instant as the rotating object passes a preset point on its path, as well as a reflector arranged on the axis of rotation of the object. The pulse laser, the optical system for forming a set of light planes, and the turret assembly are installed coaxially with the axis of rotation of the object.