Measuring the spatial polarization distribution of multimode beams emerging from passive step-index large-mode-area fibers

We measure the polarization state of each guided transversal mode propagating in step-index large-mode-area fibers (V approximate to 4) using a correlation-filter based measurement technique in combination with a Stokes parameter measurement. The entire emerging beam, expressed in terms of a phase-dependent superposition of linearly polarized modes, demonstrates spatially varying polarization properties. By knowing the information about modal amplitudes and phase differences, full information about the optical field is available. (C) 2010 Optical Society of America