Products

 400mm informative adaptive telescope

 Universal informative adaptive system

Laser adaptive system

Experimental system of super large receiving synthetic apertures

 400mm informative adaptive telescope

In the adaptive telescope a secondary mirror is made as a convex deformable mirror (DM). The wavefront sensor (WFS) is located in the Cassagrain focus (the focal ratio is about 1:8). Part of the light beam (about 70%) is used for the wavefront sensor. Other part (about 30%) forms the corrected image.

 

System composition:

  telescope with DM and with WFS
  electronic control unit
  power supply unit with the interface board
  personal computer with the software.

 

Main features of the system:

light diameter of primary mirror, mm .............................................400
light diameter of the deformable mirror, mm................................100
number of zones of the deformable mirror ....................................16
type of drives of deformable mirror is bimorph
geometry of location of drives is two rings
number of zones in external ring ....................................................10
number of zones in internal ring ....................................................6
number of positions of measurement of wavefront distortions ...16
spectral range of matrix photoreceiving device, mcm ..........0,48...1

 

 

The secondary convex mirror of the telescope is the deformable mirror.


Electronic control system ensures correction of wavefront distortions in a real-time with the band of frequencies of closed loop not less than 30Hz. Control on the common wavefront tilt in small angular range is realized by the deformable mirror itself. Special mirror with drives for tilt compensations in greater range of angles is absent.

 

 

Interface with the computer allows displaying on the monitor screen a real-time condition of electronic control unit (diagrams of voltages, spectra etc.). Besides, user can test the whole tract, including drives of the deformable mirror. Weight of the telescope is not more than 25 kG. Testing of the telescope on the near earth range with test objects under natural illumination has demonstrated a possibility of achievement of near diffractional angular resolution.

 

 

Results of the telescope testing on the 350m range.

Long exposure images of the test objects (three spots and digit "4") under condition of absence of closed loop control are on the left figures.

The right figures show images correswponding to closed loop control. Diffractional angular resolution is achieved.

 

 

 Universal informative adaptive system

This system includes complete optical-electronic unit, which is located near focus of any telescope (with focal ratio 1:7 - 1:10); it executes functions of adaptive wavefront corrector.

 

Optical-electronic unit includes:

  tilt mirror with three drives
  deformable mirror with 28 drives
  wavefront sensor
  beam splitter enabling the use of part of light beam for the corrected image

 

Main features of elements of the optical-electronic unit:

geometry of deformable mirror zones with bimorph control is two rings
number of zones in external ring........................... .......................16
number of zones in internal ring.......................... .........................12
range of tilt corrections is up to 300 diffractional angles
spectral range of matrix photoreceiving device, mcm..........0,481
size of one photodiode, mcm............................. ...........................30

Exterior of the optical-electronic unit, combined with the small telescope MTO-500 and with tiny CCD-camera WAT-508 (for registrations of corrected images), is presented on the picture.

Besides the optical-electronic unit the system includes:

  power supply unit with interface board
  personal computer with software

Electronic control system ensures a correction of wavefront distortions in a real-time with the closed loop bandwidth of frequencies not less than 60Hz. The tilt control loop bandwidth is about 10Hz. Interface with a personal computer allows to display on the monitor screen a real-time condition of electronic unit (diagrams of voltages, spectra etc.). Besides, user can test the whole tract, including drives of the deformable mirror.

 

Adaptive system was tested together with 1,1m astronomy telescope (AZT-24). During these experiments the diffractionally limited images of stars and double stars were obtained. Two images of Vega star on 1,1m astronomical telescope are presented on the picture. On the left image the closed loop control is switched off, on the right image it is switched on. The diffractional kernel and elements of the first diffractional ring are distinctly visible.

 

 


Image of double star kappa Pegasus on 1.1m astronomical telescope is presented on the picture. On the left image closed loop control is switched off, on the right image it is switched on. On the right image the star components are resolved. Angular distance between components is 0,254".

 

 

 

Your can see short videorecordings of Vega observation, kappa Pegasus observation and modelling experiment with satellite mockup on groundbased range.

Day observation of Vega

 

 

 

Kappa Pegasus observation
 
Real observation of small satellite mockup on groundbased range 400m

 

Laser adaptive system

The system is intended for correction of wavefront distortions of technological CO2 laser radiation.

 

Composition of the adaptive system:

  cooled deformable mirror with additional tilt drives
  electronic control unit
  photoreceiving device with receiving telescope
  personal computer with software

Deformable mirror has a light diameter about 120mm with 16 piezo drives. Deformable mirror control is realized without a wavefront sensor by using of well known strategy of multi frequency aperture sounding. The programable change of control law (zonal or modal) is provided. Amount of modes is programmed from 1 up to 16. Types of modes as coefficients for all drives are assigned by user.

  

Experimental system of super large receiving synthetic apertures

Experimental installation is intended for demonstration experiments in conditions of real atmospheric range on the active syntheses of super large receiving apertures in the optical range of wavelengths.


System composition:

  CO2 laser with power supply
  kit of optical elements for the receiving-transmitting scheme
  kit of optical holders with angular screws
  8-channel electronic unit
  8-channel cooled photoreceiving device
  personal computer with software
  rotating device with test objects

 


Main technical features:

wavelength of CW single mode single frequency CO2 laser .........10,6
power of laser radiation, W............................................................ 40
number of receiving apertures...........................................................8
size of each receiving aperture, mm ..........................................60x85
type of photoreceiving device is linear array of photodiodes CdHgTe
size of one photodiode, mm ..................................................300x300
distance between neighboring receiving
apertures, m (at the request of Customer) ...........0,2..3
range up to the test objects, km (at the request of Customer) ......0,5..3
time of digital processing for obtaining of one image, s ....................0,1
angular resolution is diffractional limited

Picture showes the example of montage of the receiving apertures in a pavilion of Customer. Time of the montage, adjustment and making experiments is about 23 weeks.





Results of experiments at a range about 1km. Test object are copper 5mm letters on plastic-glass substrate (bottom image). Top pictures are restored images (different stages of digital processing). Equivalent sizes of receiving synthetic aperture in the experiment are 10,5m x 100m on the wavelength 10,6mcm.







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