SU1205101A1 - Adaptive telescope - Google Patents

Description

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The invention relates to optical instrumentation, in particular, to adaptive optics and methods for controlling the wavefront, and can be used in astrophysical observations, natural resources research and in laser communication systems.

The purpose of the invention is to superimpose image quality by increasing the speed when correcting the wavefront, as well as providing the ability to calibrate the telescope.

Figure 1 shows the optical layout of the adaptive telescope; 2, an electronic circuit; on fig.Z - the image of the telescope pupil.

The adaptive telescope contains (Fig. 1) a main concave mirror 1, a secondary mirror 2 with a controllable shape, a beam-splitting plate 3, a micro-lens 4, a matrix photodetector 5, a phosphor screen 6 adapted for taking out of the beam path, a beam-splitting plate 7, a specular reflecting screen (knife) 8, having a shift perpendicular to the optical axis, lens 9, a matrix photodetector 10, lens 11, a matrix photodetector 12, a mirror reflecting screen (knife) 13, having a slide perpendicular to the optical axis, lens 14, a matrix phototop iemnik 15, the lens matrix 16 and photodetector 17. For convenience, the read circuit plate 7 and located in the reflected rays of the elements 13-17 are rotated 90 in a plane perpendicular to the plane of the drawing.

Matrix photodetectors 5, 10, 12, 15, 17 are CCD arrays

In the electronic circuit (Fig. 2), amplifiers 18–21, analog-digital converters 22–25, digital storage memory 26, logic device 27, digital-to-analog converters 28–31, and power amplifiers 32–35 are attached.

The device works in three stages. First, the device is calibrated according to the sensitivity of the photodetectors, and then by the connection between the signals of the photodetectors and the control actions on the drives, after which the actual operation of the device begins.

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The sensitivity of the photodetectors is calibrated by memorizing 26 signals in the register when the photodetectors are illuminated with a fluorescent screen 6 and dark currents when the screens 8 and 13 are removed from the path of the rays. In the future, the logic device 27 converts the measured matrix samples.

 About photodetectors, taking into account the correction for their sensitivity and dark currents.

The drives are calibrated when the telescope is aimed at a star.

15 For this, the screen 8 is moved across the optical axis by known values. The corresponding counts of the photodetectors are memorized by the register 26. Similarly, they calibrate at 20 waters according to another coordinate when the screen 13 is moved.

Next, the actual operation of the telescope begins. Screens 8 and 13 touch with their optical edges.

25 axis. Photodetector samples, carrying information about transverse aberrations, are converted by logic device 27 into normal wavefront deflections, which are transformed by a digital-to-analog converter 28 and amplifier 32 into a signal for deformation of the controlled mirror 2,

Logic unit 27 calculates the tilt values of the secondary mirror DH and uV, which are processed by digital-to-analogue converters 29 and 30, amplifiers 33 and 34, and fed to the drives.

To determine the focus error by focusing, logic device 27 calculates the value

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Claims (3)

1. ADAPTIVE TELESCOPE containing a primary v. Curved mirror, a secondary convex mirror with a frame and a shape control drive, a beam splitter plate, a wavefront sensor, a feedback device whose inputs are connected to the outputs of the wavefront sensor, and the output to the secondary shape drive mirror, and the wavefront sensor contains a beam splitter plate forming two channels, each of which includes an analyzer, a lens and a photodetector array mounted on the optical axis, characterized in that, in order to improve image quality by increasing speed when correcting the wavefront, in the wavefront sensor, the analyzers are made in the form of reflective screens inclined to the optical axis, the edges of which are located on the optical axis and in the projection onto the entrance pupil are mutually perpendicular, while in each of of channels on the optical axis formed by reflection from a reflective screen, a second lens and an array photodetector are installed, and an amplifier and an analog-to-digital converter are connected to the output of each photodetector The collator, the secondary mirror is equipped with two tilt drives mounted on the frame around two mutually perpendicular axes and a focusing drive, connected to the outputs of the feedback device, which is made in the form of a memory register and a logic unit, each of the four outputs of which are connected to a digital-to-analog converter and a power amplifier . 2. The telescope according to claim 1, characterized in that, in order to enable calibration, a phosphor screen is installed in front of the beam splitting plate in order to remove the rays from the beam, and reflective screens are arranged to move across the optical axis. 3. The telescope according to claim 1, characterized in that a micro-lens and a matrix photodetector are mounted behind the beam splitting plate on the optical axis.