Abstract: A polarized input optical beam enters a polarization beam splitter/combiner (PBC), where a first polarization component of the polarized input optical beam continues to propagate substantially entirely along a first optical path, whereas at least a portion of a second orthogonally polarized component switches onto a second optical path. A loop back optical fiber incorporated in at least one of the first and second optical paths, adds propagation delay length greater than the coherence length of the polarized input optical beam, giving rise to delayed and undelayed optical beam components, which are then incoherently recombined into a depolarized output optical beam.