Observation of spatially coherent polarization vector fields and visualization of vector singularities

We present experimental observations of polarization vector fields from a highly isotropic microchip laser with a large Fresnel number. The experimental polarization vector field leads to complex entanglement of spatial structures and polarization states. We theoretically derive the representation of generalized coherent states to reconstruct the experimental polarization- resolved patterns. The analytical and precise reconstruction enables the vector singularities to be clearly visualized.