RU1362294C - Method of determining optical thickness of disperse medium by its hologram - Google Patents

Abstract

The invention relates to atmospheric optics and reduces the measurement time. Hologram 3, obtained by illuminating the photographic material with radiation transmitted through. the medium under study is exposed to a beam of laser radiation 1. The integral component of the beam focused by lens 4 is measured. Passes to the PMT-6 using the iris diaphragm 5 only the coherent part of the radiation beam, measure its energy with a millivoltmeter 8 in the presence and absence of a hologram 3. Using the connection of the blackening of the photographic material with the light intensity, the optical thickness of the dispersion medium is determined. 1 ill. i (L s d 1 hE b s 4 ::

Description

The invention relates to atmospheric optics and can be used in meteorology, in research studies on the structure of rains and model media for the operational determination of the optical thickness of dispersed media.

The purpose of the invention is to reduce measurement time.

According to the proposed method, a dispersed medium is holographically recorded by illuminating the photo material by coherent radiation. cheni passed through the studied medium. The resulting hologram is illuminated by a coherent beam of radiation. By measuring the coherent and integral components of the focused beam passing through the hologram, and the coherent component of the beam in the absence of a hologram, the integrated transmission of the hologram t and the coherent transmission t are determined, i.e. . transmittance, which determines the portion of the transmission beam transmitted through the hologram without changing the direction of propagation. As an example, intrinsic transmission is considered. From the transmissions t and tn, t goes to blackened, P.j -lgt | j. Using the connection of the blackening of the photographic material with the intensity of the illuminating radiation and determination of the concept of optical depth, Dp-Df {, where the contrast ratio of the photographic material; E is the optical thickness of the medium; 2.718; D (j is the blackening that was created at the stage of recording the hologram by light that passed through the medium without attenuation and is scattering. D is not measured in the method. The authors first obtained the expression

(1- ,

+.

ABOUT

(2)

where Dg is the blackening determined by the veil of the photographic material and determined in the same way as from the characteristic curve of this photographic material, the Exclusion from the system of equations (1), and

(2) D, the equation for

. „-“ Chg

we get transcendental

definitions

-t.: „

ylge or in more general form

 e fi-fCt)} + f (t) о o /

about,

0

5

0

5

A specific embodiment is illustrated in the drawing.

A holographic registration of the dispersed medium is performed. To this end, the radiation of a pulsed laser, for example a ruby, is formed into a parallel beam of the required diameter using a telescopic system and sent through the dispersed medium to a photographic plate fixed in a holder perpendicular to the beam axis. Chemical photographic processing of the plate thus exposed is carried out according to standard technology.

Using a set of holders, a continuous-wave laser 1 (for example, LG-38), a telescopic system 2, the obtained hologram 3, lens A, iris 5, PMT-6 are mounted on a working plate. The size of the output lens of the telescopic system 2 and lens A is chosen larger than the size of the illuminated region of the hologram 3. The high voltage on the PMT-6 is supplied from the power supply 7j, the output signal of the photomultiplier is recorded by the millivoltmeter 8.

0 Laser radiation-1, having passed through the telescopic system 2 and formed into a parallel beam, reveals the hologram 3, installed perpendicular to the axis of the beam, and focuses /

g lysy 4. The size of the iris; we 5, located in the focal plane of lens 4, are set so that only the coherent part of the radiation beam passes through it to the PMT-6 and measure the energy E of this part (in dimensionless units) using a millivoltmeter 8. Iris diaphragm 5 is opened so that Through it on the PMT-6 all the radiation of the beam passed. Using a millivoltmeter 8, the integrated energy of the radiation beam E is measured. The hologram 3 is removed from the circuit, the size of the iris 5 is set such that only the coherent part of the sfoku passes through it to the PMT-6. sintered beam. Using a millivoltmeter 8, measure the energy of this part of the radiation beam E in the absence of

5 holograms.

From the measured values, t, t E / Ej are calculated and, using the algorithm described above, the test medium is determined.

0

5

0

Claims (1)

The claims A method for determining the optical thickness of a dispersed medium from its hologram, including holographic registration of the dispersed medium and transmission of the hologram with a coherent radiation beam, characterized in that, in order to reduce the measurement time, the radiation beam passing through the hologram is focused on, and the coherent component is measured the intensity and integrated intensity of the focused radiation beam, measure the coherent component of the intensity of the focused radiation beam in the absence of a holotfamma, and about measured. values determine the optical thickness of the dispersed medium from the Equation  f (t,) J + f (t) 0, where O is the optical thickness; C, t - respectively, coherent and integral transmission of the hologram. f (t) Igt + Dt ylg e where j (is the contrast coefficient of the hologram photographic material, D is the blackening defined by the veil of the photographic material, e 2.718. Li Editor T. Shagova Compiled by A. Vasilkov Tehred M. Khodanich Corrector about. Kravtsova Order: 1959 Circulation. .Subscription 6 NIIIPI of the State Committee of the USSR for affairs of inventions and discoveries 113035, Moscow, Zh-35, Rauska nab., d. 4/5 Production and printing enterprise, Uzhhorod, st. Projectna, 4