Research on Controlling the Polarization State of Laser Beam with a Spatial Light Modulator

Abstract

Polarization state is an important property of laser beam, and controlling the polarization state plays a key role in laser machining. By combining a spatial light modulator (SLM), a half-wave plate with a quarter-wave plate, polarization states, such as linear, circular, radial and azimuthal polarizations can be controlled. Effect of fast axis directions of the half-wave plate and the quarter-wave plate, and holograms loaded on the SLM on the polarization states is investigated based on theoretical derivation of Jones matrix. Using a polarizing filter and a CCD camera, intensity distributions are obtained at the radial polarization and azimuthal polarization, which are in good agreement with the theoretical analysis. The result proves that this simple method can be employed to realize the control of four different polarization states.