Twisted Partially Coherent Full Poincaré Beams

Full Poincaré (FP) beams that present all possible states of fully polarized light across their transverse section have received great attention in recent years. However, compared with huge successful design in coherent case, attempts in partial coherent case seem to encounter considerable challenges. It is generally believed that the difficulty of polarization change upon propagation induced by correlation seems inevitable. With the help of a new degree of freedom–twist phase, the correlation-induced polarization change is successfully eliminated. A new class of propagation-invariant twisted partially coherent FP beams are derived under specific parameter conditions to ensure complete polarization. Similar to coherent FP beams, all the polarization states of the beams are retained and covers the entire surface of the Poincaré sphere, and the propagation corresponds to a rigid rotation of the sphere. Besides, the twist phase can also be used to modulate the rigid rotation speed of the Poincaré sphere and the far-field beam spot size. The result paves the way for the design of FP beams and fully polarized vector beams in partially coherent domain and opens up new opportunities for applications such as scattering, polarization measurement, and optical sensing.