SU636486A1 - Optico-mechanical device for scanning spectrum - Google Patents

Description

1 ia (j) Hr. I iipc.ioT; ii.icna device diagram; pas figs. 2 - the course of the rays in diffraction corresponding to the maximum intensity.

The scaler is mounted on the shaft 2, the bevel wheels 3 and 4 are rigidly on the shafts 2 and 5, the gear wheel 6 is rigidly on the shaft 5, and the gear wheels 7 and 8 are installed in ball bearing onors.

The gear wheel 9 is a carrier link, on the hub of which a bracket 10 with a carriage 11 and a mirror 12 is pivotally mounted. The gear wheel 13 is also a carrier link, on the hub of which a bracket 14 with a carriage 15 and a diffraction grating 16 is hinged.

The mirror 12 is fastened in the carriage 11 by means of the nut 17 and the slider 18, and the initial setting determined by the selected angle between the diffraction grating normals 16 and the mirror 12 is carried out by means of the scaler 19 and the lead screw 20.

The diffraction grating 16 with the aid of the nut 21 and the slider 22 is fastened in the carriage 15, and with the help of the scale device 23 and the screw spindle 24, the initial setting is determined, determined by the selected angle between the diffraction grating normals 16 and the mirror 12. The gears 9 and 13 are connected by a common axis 25.

The device works as follows.

When the reading device 1 rotates, the carriage 15 with the diffraction grating 16 rotates an angle a around axis 25, and due to the gear ratio of gears 6-9 and 13, the carriage I with a mirror 12 rotates at the same time by an angle 2a around axis 25, and the plane of the mirror is always perpendicular to the radius of rotation.

The possibility of obtaining maximum intensity over the entire working range of wavelengths is justified by the following provisions.

The maximum intensity of the diffracted light occurs for wavelengths whose diffraction direction coincides with the direction of the specular reflection of the rays from the working faces of the lines of the diffraction grating. FIG. 2 shows the course of diffraction rays corresponding to the maximum intensity,

where 1 is the incident ray;

2 - diffracted beam; H - normal to the working face of the diffraction grating stroke:

P2 - normal to the plane of the diffraction grating;

H is the angle of incidence of the rays on the grating; ; p is the diffraction angle; i is the angle of brightness of the diffraction rents.

Max.ma.hn at the intensity of diffracted light corresponds to execution

CONDITIONS

 q 21 (1)

With autocollimation, the conditional is fulfilled (pg ijt, Bi. I, and the intensity maximum corresponds to the length of the lob wave. At ymaxiJJ% em, the wavelength / will be at the intensity maximum, and

/. /.ocosa, (2)

a VF, (3)

Thus, a is the angle of rotation of the lattice from the position of the brightness angle during autocollimation, which can be taken as the initial one.

According to equality (2), the intensity maximum is scanned by wavelength as the f is changed.

And in order to obtain the maximum intensity during double diffraction over the entire working spectral range, it is necessary to successively return to the grating with the help of a mirror all wavelengths corresponding to the intensity maximum, which is provided by the optical spectral scanning device (Fig. 1).

The application of the proposed device allows to obtain the maximum intensity in the entire working wavelength range of the device and makes it possible to use instead of a set of diffraction gratings one appropriately chosen grating.

Claims (2)

1. US Patent No. 3586440, cl. 356-74 1971. 2. Authors certificate of the USSR L 422976, cl. G About J 3/06, 1972. FIG. 2