Artificial multicolor guide star array emission system based on multilayer conjugate adaptive optics

Abstract

The invention discloses an artificial multicolor guide star array emission system based on multilayer conjugate adaptive optics. The system comprises a laser, a beam expanding lens group, a light splitting mechanism, an inclined reflector, a transmitting telescope and an inclined detection system; the inclined detection system comprises a wedge mirror, an inclined detector and a controller; the transmitting telescope has the functions of emitting laser and imaging a target at the same time; laser emitted from the laser device is expanded by the beam expanding lenses, then passes through the light splitting mechanism, is reflected by the inclined reflector, and is expanded and focused by the transmitting telescope, so that high-altitude sodium atoms generate primary excitation and generatea multi-color guide star array with at least two wave bands. The multi-color guide star is used for detecting and correcting the inclination aberration of the uplink path to obtain the guide star array with the determined position. The fusion and decoupling errors caused by the uncertain position of the guide star array can be obviously reduced. The performance of the multi-layer conjugate adaptive optical system is improved. The turbulence detection precision of multiple beacons is effectively improved. The structure is simple and compact, and the application range is wide.

Description

Technical field [0001] The invention relates to an adaptive optics device, in particular to an artificial multicolor guide star array emission system based on multilayer conjugate adaptive optics. Background technique [0002] The use of laser excitation to generate sodium guide stars by resonance scattering of sodium atoms at 90km to solve the problem of insufficient sky coverage of natural guide stars is currently the main method for wavefront detection in the adaptive optics system of large-aperture ground-based telescopes. The use of a single sodium guide star for wavefront detection can basically meet the needs of telescopes with a diameter of about 8m. However, the next-generation telescope has reached the level of 30m. The use of a single sodium guide star for detection has the following problems: 1) Due to the sodium guide star The height generated by the excitation is limited. The "cone effect" caused by the incomplete sampling of the turbulence on the path by the sodium...

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Problems solved by technology

The use of a single sodium guide star for wavefront detection can basically meet the needs of telescopes with an aperture of about 8m. However, the next-generation telescope has an aperture of 30m. The height generated by the excitation is limited, and the "cone effect" caused by the incomplete sampling of the turbulent flow on the path by the sodium guide star will be more obvious, thereby reducing the correction effect of the back-end AO system; 2) A single sodium signal guide star can only Two-dimensional detection of turbulence information, which limits the field of view of the AO system correction (only a few arc seconds in the visible light band), which in turn limits the application of the AO system, such as imaging extended targets (nebulae)

[0004] However, in practice, the upward pumping laser light of the guide star passes through the atmosphere, and the oblique aberration of the turbulent flow will produce a random offset unknown (ε x , ε y ), then the actual artificial guide star position is (X μν +ε x , Y μν +ε y ), but the theoretically calculated turbulence information is according to X μν , Y μν Therefore, there is an error between the restored atmospheric three-dimensional information and the actual information. Regardless of the improvement of subsequent tomographic technology or wavefront detection technology, the above problems cannot be avoided, which greatly limits the accuracy and reliability of the MCAO system. sex

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