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With the rapid development of modern science and technology in
astronomical imaging, optical communications, optical radar, optical
information processing, high-precision ranging, tracking, guidance, and
remote sensing, light waves propagating in the medium, especially in the
turbulent atmosphere spread more and more important. Atmospheric
turbulence is one of the main factors which have influence on the
performance of a laser communication system. Adaptive optics technology
is an important means to solve the problem of atmospheric turbulence. This
paper states how adaptive optics technique can be used in space laser
communication system to compensate atmospheric turbulence when laser beam
transmission through it. The core content of adaptive optics is correct
laser beam wave-front disturbance in real-time，with it to enhance optical
system imaging quality and the next aim is reach the level of diffraction
limitation. Adaptive optics system consists of wave-front detection，
wave-front control and wave-front correction . The demo platform
including: atmospheric turbulence simulation unit、adaptive correction
unit、signal transmitting and receiving unit. Liquid crystal spatial light
modulator applications in adaptive optics system and the turbulence
simulation system introduced. And used zernike polynomials method to
produce atmospheric turbulence phase screen simulation analysis.
Simulation results show that: in the low spatial frequency components,
the atmospheric turbulence phase screen generated by Zernike polynomial
method consistent with the theoretical values, but in the high spatial
frequency components, the simulation results with large difference
between the theoretical values. In addition, the simulation results also
show that: we can change the distribution of turbulence in the atmospheric turbulence phase screen by increasing the Zernike polynomials of orders
or change the receiving apertures, but to calculate the large calculate
the complex and other shortcomings. If adaptive optics technique can be
applied in space laser communication system and is proved by practice，
must make a space laser communication system performance has greatly
improved.
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