SU1179744A1 - Interference-shadow device - Google Patents

Abstract

INTERFEGENTAL-SHADOW DEVICE containing a light source, a lens located at the interferometer output, a visualizing aperture, a schlieren photographic recording unit and an interferogram recording unit, characterized in that in order to preserve the light flux and ensure spatial filtering of the interference pattern while simultaneously registering the shadow and an interference pattern, the visualizing diaphragm is made in the form of a mirror with a transparent hole or a mirror-reflecting screen on a transparent layer and set to focus the lens, and it is the plane with the optical axis and the direction to the node registration shpiron images equal angles. (L

Description

with vj

i (

The invention relates to interference shadow devices and can be used to study phase inhomogeneities: plasma gas flows and jets, flames, shock waves in gases and liquids.

The aim of the invention is to preserve the luminous flux and ensure the spatial filtering of the interference pattern while simultaneously registering the shadow and interference patterns.

The drawing shows the optical layout of the device.

The device consists of a point light source 1, translucent mirrors 2 and 3 of the interferometer, opaque mirrors 4 and 5 of the interferometer of the collimator lens 6, the lens of the recording system 7, the phase irregularity 8 under study, the visualizing aperture 9, the schlieren photograph photographic node . The diaphragm 9 is made in the form of a mirror with a transparent aperture or a specularly reflecting screen on a transparent layer and is set in the focus of the lens, and its plane is equal angles with the optical axis and direction to the schlieren-photography unit. The diameter of the hole in the diaphragm depends on the parameters of the optics used, the nature of the heterogeneity under study and lies within

P.d.2fJ§ di.

E where f is the focal length of the lens 7;

n is the refractive index of the object under study;

797442

1 - path length in the studied

heterogeneity;

p is the size of the source in the plane of its image formation.

The device works as follows. Radiation from source I by mirror 2 is divided into two channels: reference and measurement. The radiation beam of the reference channel is reflected from mirror 5 and is fed to mirror 3. The beam of the measuring channel is reflected from mirror 4, the inhomogeneity 8 passes through and

15, the mirror 3 is mixed with the beam of the reference channel. The reference beam, as well as part of the object beam of the measuring channel, having passed the inhomogeneity under study without deviation (or deflected at a small angle determined by the diameter of the hole in the diaphragm 9), passes through the holes of the diaphragm and forms an interference pattern in the plane of the recording node 10. This pattern is formed only that part of the subject wave that has not undergone refraction. Rays of light, rejected by the investigated heterogeneity, are reflected from the mirror portion of the imaging diaphragm 9 and are directed by it to the registration channel of the shadow pattern in the plane of the recording unit 11.

Thus, the imaging aperture 9 and its location in the focus of the lens in the manner shown in the drawing, while registering the shadow and in .Q of the interference pattern, simultaneously exclude light losses and spatial filtering of the interference pattern.

Claims (1)

INTERFERENCE-SHADOW DEVICE containing a light source, a lens located at the output of the interferometer, visualizing the diaphragm, the registration unit of the fire-line photograph and the registration unit of the interferogram, characterized in that, in order to preserve the light flux and provide spatial filtering of the interference pattern at simultaneous registration of the shadow and interference patterns, the visualizing diaphragm is made in the form of a mirror with a transparent hole or a mirror-reflecting screen on a transparent layer e and set to focus the lens, and its plane forms with the optical axis and the direction at the reception node shliron images equal angles.