SU123745A1 - Compensator for the difference in the course of light rays in a polarimeter, designed, for example, to study models using the photoelasticity method. - Google Patents

Description

The known instruments for measuring and recording changes in the difference in the course of the light rays with time do not allow measuring their constant and variable components simultaneously.

The proposed device allows one to automate the process of compensation and recording, in view of which it can measure not only a constant, but also a time-varying difference in the course of the light rays. In the electrical compensator, the Kerr capacitor was used to measure the optical path difference in the model studies using photoelasticity, and the oscillograph tube was automatically recorded on the screen of the oscillographic tube, which makes it possible to record the time difference of the beam, which is also variable in time. To provide a change in the path difference of the rays by more than two hours of light, a sawtooth voltage is applied to the Kerr capacitor.

FIG. 1 shows the block diagram of the device.

Here: / is the source of monochromatic light; 2 - lenses: 5 prisms Nicol; 4 - model. A sawtooth voltage is applied to the Kerr o capacitor from the generator, which depletes the difference in travel by more than two wavelengths of light — if the model is not present in the field of the risk box, then the current change in the photomultiplier 7 is crooked; / on . 2. If a model with a certain path difference is entered into zero meter, then the current at the output of the photomultiplier 7 will receive a certain phase shift relative to its initial position (curve // in Fig. 2). The magnitude of this shift is determined by the difference in the course of the model introduced and can be

No. 123745-2 -

used as a measure of the latter. If we notice on the curve / the voltage corresponding to any characteristic point, then by measuring the voltage according to its point on the curve, we can determine the difference in the course of the model. For measuring and recording the voltage on the capacitor 5 at the time of reaching a characteristic point, there are blocks that are included after the photomultiplier 7. Amplifier-limiter 8, in addition to the amplitude of the signal, limits its amplitude, so that the output voltage is close to rectangular. The differentiating chain 9, connected behind the limiting amplifier, generates voltage peaks of characteristic points, which are fed to the pulse generator 10 to increase their power. To register the voltage on the capacitor at the time of the pulses amplified by the generator 10, an oscillographic tube 11 is used. indicated in FIG. 1 with the number 12. The image from the screen of the tube is fixed on the film.

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The compensator of the path difference of the light beam in zero rimet) e, designed, for example, to study models by photoelasticity, made in the form of a Kerr capacitor, characterized in that, in order to increase the change in the path difference of the rays by the Kerr capacitor, it is connected to the generator circuit stress mon / juvenile shape.

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