Coherent Inverse Compton Scattering Responsible for Pulsar Polarized and Unpolarized Emission

A coherent inverse Compton scattering(ICS)mechanism is used to get polarization properties of radio emission of pulsars.It is found that particles moving along a ring with radius θ’=1/(√3γ)simultaneously contribute via coherent ICS.The circular polarization can be easily gotten as well as linear polarization at the same time.Our theory releases the upper limit of Lorentz factor γ≤20 put by curvature radiation,and γ may take several thousands in ICS.Furthermore,subpulse position angles do take diverse values,while mean position angle is associated with the projection of magnetic Geld lines.So it is natural to get commonly-seen S-shaped swing of mean position angles.Finally we present a simulation for position angle rotation,linear polarization,circular polarization of PSR1508+55,which means that the coherent ICS may be responsible for radio emission.