SU1552140A1 - Method of optical measuring of intensity of pulsed electric or/and magnetic field - Google Patents

Abstract

The invention relates to a pulse technique and is intended to measure the electric and / or magnetic component of pulsed electromagnetic fields. The purpose of the invention is to improve the measurement accuracy while simplifying the device for implementing the method. In the device implementing the method, the luminous flux of the source of plane-polarized light 1 passes through the optical active element 2 and the birefringent analyzer 3 is converted into two paraphase-modulated beam signal, which are converted by avalanche photodetectors 4 and 5 into electrical output signals U ₁ and U ₂ , summed further by the adder 6. The goal is achieved by the output of the operational amplifier 8, its inverting input through a resistor 7 connected to the output of the adder 6, with which through a resistor 9 is also connected and the output of the operational amplifier 8 is formed voltage U _Ex = K [U _fl - K ₁ (U ₁ + U _2)] + U _fl, where U _fl - reference voltage at the noninverting input of the operational amplifier 8, K and K ₁ — proportionality coefficients, which synchronously and in-phase control the conversion factors of the photodetectors 4 and 5. 1 sludge.

Description

The invention relates to a pulsed equipment and is intended to measure an electric or / and magnetic field of a pulsed electromagnetic field.

The aim of the invention is to increase the measurement accuracy while simultaneously simplifying the device for reaization of the method.

The drawing shows a functional diagram of the device that implements the manual.

The device contains a source 1 of plane-polarized light, the light J5 from which is dropped into the optical active element 2 and then analyzed by a birefringent analyzer 3, rays of light from which fall on avalanche photodetectors 4 and 5, the outputs of which are outputs devices. The inputs of the summing device 6 are also connected to them, the signal from the output of which through a resistor 7 is fed to the inverting input of the operational amplifier (SU) 8. The non-inverting input of the OU 8 is supplied with the reference voltage U3T, and the output signal of the OA 8 feeds the avalanche photodetectors 4 and 5, with the output of the op-amp 8 through 30 the resistor 9 is also connected to its inverting input.

The device works as follows.

If the birefringent analyzer 3 is oriented in such a way that, in the absence of the field to be measured, the plane of polarization of the incident light of source 1 is located symmetrically relative to the planes of the ortho-tonal polarized component of the transmitted light and an optical (magnetic) field then the intensities of the orthogonally polarized components of the light passing through the analyzer 3 each contain two. components. The first component does not depend on the intensity of the measured field, which is proportional to the total optical power transmitted through the device. The second component is proportional to the product of the total optical power and the sine of the angle y, resulting from a rotational rotation of the polarization plane proportional to the intensity of the measured field. If the angle of rotation does not exceed 1G / 10, the second part35

O

5 0 5 0

0 45 $ d, s

five

It can be considered proportional to the product of the total optical power transmitted through the device by the intensity of the measured field.

The signals at the outputs of photodetectors 4 and 5 also have two components each. The first one is in-phase — proportional to the total optical power, and the second — parfazne — is proportional to the product of the total optical power and the intensity of the measured field. The summation of these signals at the output of the adder 6 produces a signal proportional to the total optical power. This signal, arriving at the inverting input of the OA 8, is subtracted from the reference signal; la ujt filed on non-inverting input.

Photodetector output signals

4 and 5 in the approximation of the equality of their conversion factors S and the load resistances F for small measured signals () are {respectively

utj2- I s..p (ttf), (i)

where P is the light power. (. The signal at the output of the adder 6 does not depend on the measured value (from yj

U5 K.CU.,. U7) S-R-P, (2)

where K 1 is the transfer coefficient for summation. The voltage at the output of the shelter 8 has the form:

U, np K iat-K, (U, + and) +

+ U

at

(3)

where it is the reference voltage, the transfer coefficient of the subtraction operation, Rtn R is the resistance of the resistors 7 and 9.

With small fluctuations of dp of light power around its average value of p0 (p P0 + dP, dP P0) accordingly, the signal at the output of the adder 6 Gu-j - U 0 + dU, dU " V 0 fluctuates. Reli U3T U0, then according to (2) and (3) at the output of OU 8 takes place

U

ur

 U FL - KdU,

those. fluctuations in light power cause antiphase voltage fluctuations U, feeding the photodetectors 4 and 5. Taking into account the form of the coefficient

that transform the scsfl-cu / u lazinky photodetector

Control

Where

Un is the breakdown voltage, n (1-3) is the technological coefficient, it is clear that the control signal generated by the algorithm (3) provides a synchronous compensation for the effect of the fluctuations of light power on the output signals (1).

The selection of the coefficient K (in the concrete implementation is the ratio of the resistances of the resistors 7 and 9) and the stability of these signals is brought to a level determined mainly by the stability of the reference voltage

and., t,),

what provides an increase in the accuracy of measurements by a known method. In this case, for the implementation of the proposed method, there is no need for a subtractor device and an analog divider, which are fundamentally necessary in a known device. In addition to simplifying the implementation device, the exclusion of these blocks also excludes errors introduced by them, i.e. additionally improves measurement accuracy.

Claims (1)

Invention Formula A method of optical measurement of the intensity of a pulsed electric Q 52) 406 or magnetic field, which means that the polarized luminous flux is passed through the optical active element, after that the luminous flux is converted into two para-modulated luminous flux, the two fluxes are converted into the corresponding output U 2 coelectric signals and, and then, then summarize, in order to improve accuracy while simplifying the device for implementing the method, it forms a control signal to the expression Yiw, rsog U Where go on T   -, + ut) 3 u, t, ET - constant voltage, the value of WHICH is direct proportional to the product of the average power of the luminous flux by the nominal number of: the conversion of the luminous flux into an electrical signal; K and K1 - proportionality coefficients, whereby the coefficient of conversion of light fluxes into electrical signals is synchronously changed when the signs of the increments of the control signal and the coefficient of conversion of light fluxes into electrical signals coincide.