SU1383273A1 - Controlled fresnel optical wedge - Google Patents

Abstract

The invention relates to optical instrument making and allows to expand the range of variation of the coefficient. loosen and ensure smooth adjustment. In the attenuator, the beam-splitting element is made in the form of a plate 9, the plane of which is aligned with the axis 7. The radiation beam directed by mirrors 10, 11 is inserted into the system of reflecting mirrors 1-4 installed at an angle of 90 °. each other, is output from the attenuator by mirrors 12, 13. The coefficient. attenuation of the incident radiation beam is due to the angle of inclination of the platforms 5 and 6 with pairs of mirrors 1.4 and 2.3 respectively to the plane of the plate 9. The change in the number of passes of the radiation beam through the system of mirrors 1-4 is performed by moving the mirror 3 in the plane of the platform 6. One of the mirrors in each pair of the system is made dihedral with the angle between faces 90. 3 hp f-ly, 3 ill. iS

Description

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This invention relates to optical instrumentation and can be used to attenuate the intensity of optical radiation, for example, in measurement technology, laser therapy and surgery, etc.

The purpose of the invention is to expand the range of variation of the attenuation coefficient and at the same time ensure its smooth adjustment.

FIG. Figure 1 shows the basic optical scheme, as well as the arrangement of the reflecting surfaces on the moving platforms of the controlled Fresnel attenuator, top view in FIG. 2 is a diagram of the operation of a controlled attenuator when operating with a reflected radiation beam, left view; in fig. 3 is a schematic diagram of the implementation of a device controlled by Fresnel electrically weakened attenuator.

The attenuator (Fig. 1) contains a system of four (fully) reflecting mirrors 1-4, constituting the ring circuit and installed in pairs on two platforms 5 and 6, having the ability to rotate around the axis 7 of the fixed base 8. The beam splitting element, for example, a wedge or plane-parallel plate 9, is installed so that the axis 7 of the fixed base 8 passes through its plane (plates 9), and the normal, lowered on this plane, crosses the axis of the fixed base and divides the angle between the consistently rotating platforms 5 and 6 in half. The mirrors of the input 10, 11 and the output 12, 13 are mounted on one of the rotating platforms 5 and 6, for example on platform 5. One of the reflecting mirrors, for example 3, is installed on platform 6 with the ability to move in the plane of the platform. The movement is carried out, for example, by means of a micrometer screw 14 and a nut 15, rigidly connected to the mirror 3 along guides.

The attenuator works as follows.

The Beam of Radiation (Fig. 1), which is successively reflected from the input mirrors 10 and 11, falls on one of the reflecting mirrors (mirror 1), forming an annular circuit. Reflecting mirrors 1-4 circular are mounted so that the radiation beam is reflected from. each of them several times and is output from the attenuator using mirrors 12 and 13 of the output. In this case, mirrors 1 and 4 are placed on platform 5, and mirrors 2 and 3 are located on platform 6. In the initial position, when attenuation of the radiation beam does not occur, the planes of platforms 5 and 6 coincide between each other, And are parallel to the plane of the partially absorbing wedge (plane-parallel plates) 9. If we install platforms 5 and 6, having an axis of rotation 7, at a certain angle to the plane of the beam-splitting element (Fig. 2), for example, a wedge or a plane-parallel plate 9, then a beam of radiation passing through an annular scheme of mirrors 1-4 will be consistent partially reflected from the surface of the beam-splitting element 9, and the number of such reflections will correspond to the number of passes of the radiation beam through the ring circuit. mu looser. Thus, consistently changing the angle of inclination of each of the platforms 5 and 6 with respect to the plane of the beam-splitting element 9, the angle of incidence of the radiation beam on the plane of this element is also changed, and therefore, in accordance with the known Fresnel formulas, the attenuation coefficient of the incident light also changes. radiation beam.

In position I (Fig. 2) of the platforms 5 and 6, the attenuation of the beam is minimal (sliding incidence), and in position II corresponds to the greatest. attenuation (beam fall, close to normal).

To change the number of passes of a radiation beam through an annular attenuator circuit, one of the mirrors (3) of the annular circuit must be installed, with the possibility of its movement in the plane of the platform (6), for example, by means of a screw 14 and a nut 15 rigidly connected with this mirror . FIG. 1, position I of mirror 3 corresponds to six rotations of the radiation beam through an annular circuit, position II to four passes, position III to two passes.

The specific embodiment attenuator (Fig. 3) contains mirrors 1-4, forming an annular circuit and arranged in pairs on two platforms 5 and 6 rotating around axis-7 of the fixed base 8, beam-splitting element 9, also having the ability to rotate around the indicated

Axis 7.) The layer () itel also consists of two prism rhombuses 16 and 17c with a mirror coating coated on their end faces, which serve to enter and output radiation into the attenuator ring circuit and VI3. The rotation of the platforms 5 and 6 is carried out using, for example, bevel gears 18 and 19, rigidly connected with corresponding platforms on their axis of rotation, kinematically connected to the electric motor 20 by means of bevel gear 21, mounted on the shaft of the electric motor 20. Thus When the motor is turned on, the platforms rotate at the same angular speed, but with the opposite sign. The platforms 5 and 6, as well as the element (plate) 9, are connected to the axis 7 of the fixed base 8 by means of rolling bearings 22-27.

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Claims (4)

1. A controlled Fresnel attenuator containing a beam-splitting element and a system of four mirrors installed at an angle of 90 ° to one another, characterized in that, in order to extend the range 50 five about changes in the loosening factor of the patient and ensuring its smooth adjustment, the beam splitting element is mounted on the axis, the axis being aligned with the plane of the beam splitting element, and each pair of mirrors is installed on the platform with the possibility of turning about the axis. 2. The attenuator according to claim 1, characterized in that, in order to increase the convenience of operation, two flat mirrors are installed on both sides of the system of four mirrors, parallel to each other and at an angle of 45 to the beam splitter. 3. An attenuator in PP, 1 and 2, which is characterized by the fact that, in order to increase the attenuation adjustment range, one of the system mirrors of four mirrors mounted on a platform with the possibility of movement along the axis. 4.The attenuator in paragraphs. 1 to 3, which is due to the fact that, in order to improve the accuracy of the attenuation coefficient adjustment, one of the mirrors of each pair of c (two of the four mirrors are double-faced with an angle between the faces 90. / 15 AT 2 (m k X L .. 77 Fig.Z