A Research On The Polarization Of The Laser In Atmospheric Laser Communication System

With the rapid development of laser communication technology, polarization modulation has been gradually applied in the atmosphere laser communication after succeed in fiber-optic laser communications. For in-depth research on the polarized light of polarization characteristics and transmission regulations in the atmosphere laser communication, the corresponding detection system came into being.In this paper, a polarimetry based on the liquid crystal variable retarder, in the method of Stokes parameters, uses the liquid crystal variable retarder instead of the rotation of the waveplate driven by the motor in the traditional measurement. It controls the birefringence factor of liquid crystal by changing the voltage, precisely control the polarization state of the input light and thus accurately measures Stokes parameter to obtain the polarization parameters.The liquid crystal variable retarder which is adjustable by voltage overcome abrasion caused by the rotation of the waveplate, motors or other moving parts and vibration source caused by mechanical movement. It eliminates the mechanical error. LabVIEW graphical programming language is used to process the data, display the result, save the information and print. Not only to make the design of programme simple and intuitive, but also make the customer interface simple and humanity.