SU1194144A1 - Method of determining properties of optically active objects and device for effecting same - Google Patents

Description

The invention relates to an optical measuring technique and can be used to study the properties of transparent optically active media, for example, when measuring concentrations of substances and populations, atomic levels, when measuring magnetic fields in a plasma, when studying the effects of parity nonconservation with weak interactions in atoms, in analyzing the molecular structure of matter, in determining the oscillator strengths of atomic transitions, in determining the constant Verde substances, in studying nonlinear optical phenomena and in a number of other tasks.

The purpose of the method and device is to increase the sensitivity in determining the properties of optically active objects.

Figure 1 shows the structural diagram of the device, figure 2 is an example of a specific implementation; on fig.Z dependence of the magnitude of the magnetic rotation ⁴ ? polarization plane from the current through the solenoid.

The device comprises an optical pumping unit 1, optically coupled via a delay line 2 to an active medium 3.

The active medium and the emitted object 4 are placed in an optical resonator, obozovanny mirrors 5 and 6. Block 7 external indicative radiation is optically connected with the active medium (mirrors 5 and 6 partially transmit radiation). Radiation unit 7 is introduced along the axis of the resonator.

The operation of the device is as follows.

one

Unit 7 is started synchronously from the pump unit in such a way that the initiating radiation is in the active medium before the radiation of the pump unit. This prevents the development of generation from spontaneous radiation. Adjusting the synchronization is carried out by changing the magnitude of the delay of the pump pulse in block 2.

10 Part of the generation radiation is released through the mirror 6 and is sent to the registration unit 8, where the angle of rotation of the polarization plane is measured. Thus, probing radiation

15 repeatedly passes through an object that rotates the plane of polarization and through an active medium that compensates for the loss of light.

ι on absorption, reflection and scattering in the resonator.

The optical pumping unit 1 is an OGM20 ruby laser operating in the giant pulse mode. Translucent mirror 9

25 divides the pump radiation into two approximately equal parts. The optical delay line 2 is formed by mirrors 10–12. with a reflection coefficient of about 100%. The resonator of the main laser is formed by mirrors 5 and 6 with dielectric coatings, which have reflection coefficients of 50! And 100%, respectively.

The active medium 3 is an ethanol solution of a polymethine dye. As the investigated object 4 is used in a cuvette with water in a longitudinal magnetic field. Block 7 initiating radiation represents

4θ is a laser (seed) for beauty3

body (the same as in the main la · zere). The dye solution is in a cuvette. The resonator consists of a diffraction grating (600 lines / mm, 1st order) 14 and a translucent mirror 15. Telescope 16 (magnification 10) makes the grating more efficient. Radiation polarized in the plane of incidence on the grating 14 and perpendicular to it and propagating from the active medium 13 in the direction of the diffraction grating is refracted by Wollaston's prism 17 at different angles. As a result, the seed laser emits two wavelengths with orthogonal polarizations. The radiation of the initiating unit is injected into the main laser using mirrors 18 and 19 with dielectric coatings, the reflection coefficients of which are 100% and 50%, respectively.

The registration unit 8 consists of a Fabre-Perot interferometer 20 transmitting radiation from only one of two

1194144

wavelengths, and a balanced rotation angle registration scheme operating in the integrated registration mode.

A 45 is used (Frank-Ritter polarization prism position 21 geometry. Part of the radiation is removed with a glass plate 22 (normalization signal). F-28 pulsed photocells are used as radiation receivers 23-25. Pulsed supply voltage 1.5 kV. Pulsed Voltmeters 26 and 27 of type B4-17 provide digital indication of the recorded signals.The parameters of the integrating circuit 15 in the registration circuit: 11 = 0.5 MΩ, C = 100 pF.

The OGM - 20 radiation is linearly polarized in the plane of incidence of light on the mirror 9 for the purpose of (creating isotropic, inversely populated environments 3 and 13 with the transverse geometry of pumping dyes.

The cylindrical lenses 28 and 29 create the power density necessary for the development of the generation.

1194144

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Claims (2)

1. A method for determining the properties of optically active objects, which consists in passing linearly polarized monochromatic probe radiation through the object under study and the inversely populated medium in the resonator and measuring the angle of rotation of the polarization plane, which is used to judge the properties of an optically active object that is distinguished by In order to increase the sensitivity of the measurements, probe radiation is transmitted at two wavelengths with orthogonal polarizations. Zi „„ 1194144 I 1194144 2, The device of the day for determining the properties of optically active objects, containing a resonator with a holder of an optically active object and an inversely populated medium, a pumping unit, a source of probe radiation and a recording system, characterized in that, in order to increase the sensitivity of measurements, a unit of formation of two-wave orthogonal polarizations of the probe radiation optically coupled to the source of the probe radiation, and the inverse population medium is optically coupled to the pulsed pumping unit through cally delay line, wherein the pump unit is combined with a source of probing radiation. one