TURN Ltd. is one of a few firms in the Optical and Laser Community who offer a novel, most advanced and promising high-technology product - technique providing a real-time control over the wavefront of optical radiation.
Field of appfication: controllable optics, in particular, astronomic telescopes, industrial laser instruments, optical systems of guidance and tracking.
The modules enables the user to exert a control over wavefront distortions of optical radiation and to compensate phase distortions in a variety of optical systems and devices.
Existing systems suffer from a number of disadvantages. Among them are an inability to control surface deformations in spacings between adjacent piezoceramic plates, a high labor intensity of the mirror production process, especially of optical surface forming, a low reliability and strength of the construction, a low quality and instability of the optical surface initial shape, an existence of the electrical potential on the mirror metallic body, small range of optical radiation phase distortions that can be compensated; a low sensitivity and accuracy of phase correction with no possibility of its further improvement; low allowable level of incident optical radiation power (not exceeding 1 kW)
Suggested devices are high-technology inventions, overcoming all the abovelisted disadvantages and provides a wide variety of possibilities. For example, phase distortions can be compensated due to utilisation of an advanced deformable bimorph mirror made as a semi-passive bimorph structure; increased accuracy of correction of optical radiation phase distortions results from the increased number of phase control channels; an increased allowable level of incident optical radiation power provides by the presence of a cooling system; a simplification of the system reached by the replacement of a special mirror for a dynamic tip/titl wavefront control with a dynamic positioning as well as by the reduced voltage applied to the deformable bimorph mirror and replacement of high-voltage control units with a low-voltage apparatus.
Proposed mirrors have a sleeve-shaped housing with a cover. Outer surface of its bottom serves as a reflecting optical layer. Inner surface serves as a control layer made of one or several piezoelectric elements arranged over the surface as a mosaic. Each element may be made of two and more layers of piezoceramic plates.
AT22 and AT24 adaptive mirrors.
Unique technical solutions provide low cost, small weight and dimensions of the mirror. The mirror can be made using standard industrial equipment, materials and technology.
The systems demonstrate a number of additional unambiguous advantages, including a simple construction (a minimum kit of ultimately simple optical and electronic components); a possibility to create a compact optoelectronic unit containing the total module in one housing (this enables one to use such a unit as an optional attachment to any kind of laser system in order to improve its performance); and other.
The present inventions are used successfully in optical systems for a dynamic correction of optical beam axial-symmetric distortions with a high degree of accuracy. For example, the applications of the inventions to laser systems with "flying" optics provides a weld of uniform quality over the whole area under processing.
REAL-TIME CLOSED-LOOP CORRECTION ARCHITECTURE
Real-time control over the wavefront of optical radiation
Adaptive optical system comprises the following main components:
- Deformable mirror (DM): multilayer bimorph design; cooled/non-cooled; max 24 m of surface displacements, up to 1 kHz of frequency range.
- Multichannel control electronics: +/- 300 V of output voltage, frequency bandwidth up to 1000 Hz
- Optical sensor: wavefront sensor