Polarization Transmission Matrix for Completely Polarization Control of Focal Spots in Speckle Field of Multimode Fiber
Weiru Fan, Ziyang Chen, Li Chen, Liqing Wu, Xuanxuan Ji, Jixiong Pu
Abstract
The propagation of light transmitting through a scattering medium generates random speckle. Transmission matrix (TM) is introduced to describe this transmission process. In general, only scalar TM is considered. Meanwhile, for a nonpolarization maintaining multimode fiber (MMF), depolarization effect is extremely strong. Therefore, the field at the exit end of a MMF is a speckle with random distribution not only in terms of intensity but also polarization. In addition to traditional TM, we propose polarization TM (PTM) to describe the depolarization effect of a MMF. Based on PTM, the speckle pattern formed by a coherent light transmitting through a MMF can be modulated into one focal spot or multiple focal spots with desired polarization.