SU1619031A1 - Optical electric device for forming and space following modulated optical beam - Google Patents

Abstract

The invention relates to a measurement technique, in particular to devices for spatial tracking of the position of modulated optical beams with a flat signal zone. The purpose of the invention is to improve the accuracy and expand the range of spatial tracking. The device contains an optical unit 6, forming an equisignal zone and having two illumination channels, containing optical sources 1. 2 radiation and capacitors 3, 4, photo-recording unit 12, containing objective 13 and photodetector 14, electronic processing circuit containing amplifier 15. phase detector 16 , indicator 17 and power amplifier 18. The electronic circuit of the device generates an error signal when the axis of the radiation beam, formed by the optical unit 6, is displaced from the optical axis of the photorecording unit 12. Complete The optical unit allows for the reduction of spherical aberrations. 2 Il. ate

Description

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The invention relates to a measuring and control technique, namely, optical-electronic devices that form and track the spatial position of modulated optical beams with equivalent zones and can be used to measure the profiles of polished surfaces.

The purpose of the invention is to improve the accuracy and broaden the range of spatial tracking.

Figure 1 is a schematic diagram of the device; figure 2 - section aa in figure 1.

The device contains a radiation system consisting of two pairs of optically coupled source 1 (2) of radiation and a capacitor 3 (4), block 5 of antiphase supply of radiation sources, two outputs of which are connected respectively to the inputs of sources 1 and 2 of radiation, an image transfer system, made in the form of a cylindrical optical transparent block 6, consisting of two half-cylinders, on the lateral surface of which symmetrically relative to the plane of their connection and parallel to it are rectangular grooves 7, the base cylinder The drift block is curvilinear and forms a lens 8, the optical axis of which coincides with the axis of the optical block and lies in the plane of the junction of the semicylinders, the other base of the cylindrical block is made in the form of a dihedral angle, reflecting the faces of the beam splitter 9, made on each of the semi-cylinders at equal angles to the plane of their connection, and the edge of the dihedral angle perpendicular to the axis of the optical unit and placed in the focus of the lens, sources 1 and 2 of the radiation are placed These are opposite the respective rectangular grooves so that their optical axis is perpendicular to the axis of the optical block and the edge of the dihedral angle and passes through the point 11 of their intersection. The device also contains a photo-registering unit 12, consisting of a lens 13 and a photodetector 14 placed at its focus, and an electronic signal processing circuit including an amplifier 15 connected in series, the input of which is connected to the output of the photoreceiver 14, a phase detector 16 and an indicator 17, and a power amplifier 18, the input of which is connected to the output of the phase detector 16, the second input of the latter is connected to the antiphase power unit 5.

The device works as follows.

The radiation system forms a parallel beam, which has a pronounced equal-signal zone (RSZ) along the optical axis of the cylindrical optical unit 6, which is due to a sudden change in the properties of optical radiation along this axis, due to the fact that sources 1 and 2 emit radiation at the same frequency, but in antiphase. The radiation is perceived by the lens 13 of the photoregistrating unit 12 and directed to the photodetector 14, from which the signal is taken, described by the following formula:

U - S -smart (-), where S is the steepness of the photodetector;

w-round modulation frequency; t is time;

Fu) a radiant flux, the modulation phase of which is assumed to be zero;

  radiant flux, the modulation phase of which is shifted by 180 °.

It can be seen from the formula that if the flux Φ (and Fue-180 are equal, which is possible only when the axis of the radiation beam coincides with the axis of the photoregistering unit 12, the signal taken from the output of the photoreceiver 14 is zero. When the axes of the optical unit 6 are not the same and the photoregistrant The signal from the photodetector 14 is different from zero in block 12. The voltage removed from the output of the photoreceiver 14 is amplified in amplifier 15 and fed to a phase detector 16, where the sign of the beam's bias is detected. The magnitude and sign of the bias are recorded on the indicator 12. From the phase detector The aperture 16 enters the power amplifier 18 and further to the actuator, which moves the photoregistrating unit 12 relative to the beam axis of the optical unit 6 until the axis coincides with the axis of the lens 13. Thus, the device monitors the spatial position of the modulated light beam. 6, the lens of which is designed as a single refractive surface, almost completely eliminates spherical aberrations, which gives a significant increase in the accuracy of transitive beam tracking.

Claims (1)

An optical electronic device for generating and spatially tracking a modulated optical beam, comprising a radiation system consisting of two pairs of optically coupled radiation sources and a condenser and an antiphase power unit, two outputs of which are connected respectively to the inputs of two radiation sources, an image transmission system and a photoregistration unit sequentially arranged along the radiation path, an electronic processing circuit, characterized in that, in order to improve the accuracy and extend the range of spatial tracking, the image transmission system in the form of a cylindrical optically transparent block consisting of two half-cylinders, on the side surface of which they are symmetrical with respect to p oskosti compound and parallel to the rectangular grooves formed cylindrical base unit holds and curved 0 five forms the lens, the optical axis of which coincides with the axis of the optical block and lies in the plane of the junction of the semicylinders; the other base of the cylindrical block is made in the form of a dihedral angle, the reflecting faces of which are the beam splitter formed by chamfers made on each of the semicylinders at equal angles to their plane the edge, and the edge of the dihedral angle is perpendicular to the axis of the optical unit and placed at the focus of the lens, the radiation sources are placed opposite the corresponding rectangular grooves so that their optical axis is perpendicular to the axis of the optical block and the edge of the dihedral angle and passes through the point of their intersection. FIG. 2