Complete polarization control in multimode fibers with polarization and mode coupling

Abstract

Multimode optical fibers have seen increasing applications in communication, imaging, high-power lasers, and amplifiers. However, inherent imperfections and environmental perturbations cause random polarization and mode mixing, causing the output polarization states to be different from the input polarization states. This difference poses a serious issue for employing polarization-sensitive techniques to control light–matter interactions or nonlinear optical processes at the distal end of a fiber probe. Here, we demonstrate complete control of polarization states for all output channels by only manipulating the spatial wavefront of a laser beam into the fiber. Arbitrary polarization states for individual output channels are generated by wavefront shaping without constraining the input polarization. The strong coupling between the spatial and polarization degrees of freedom in a multimode fiber enables full polarization control with the spatial degrees of freedom alone; thus, wavefront shaping can transform a multimode fiber into a highly efficient reconfigurable matrix of waveplates for imaging and communication applications.

Wave condensation with weak disorder versus beam self-cleaning in multimode fibers

“…In the previous section III A 1 we have considered a model of disorder that can be termed 'modedecorrelated', in the sense that each individual mode of the MMF experiences a different noise, i.e., the functions ν p,j (z) in (9) are independent of each other. Although this approach can be considered as justified in different circumstances [47,51,52], one may question its validity for a MMF featured by a large number of modes. In the following we address this question by considering two different models of disorder, namely the fully mode-correlated disorder model, and the partially modecorrelated disorder model.…”

“…[41] a previously unrecognized mechanism of acceleration of condensation mediated by disorder has been reported, which can help to understand the effect of beam self-cleaning. Indeed, light propagation in MMFs is known to be affected by a structural disorder of the material due to inherent imperfections and external perturbations [44,45], a feature which is attracting a growing interest, e.g., in image formation [46,47], or to study the dynamics of completely integrable Manakov equations [48][49][50][51][52][53].…”

Thermodynamic theory of highly multimoded nonlinear optical systems

“…Recent years have witnessed a strong comeback of multimode (MM) fiber technologies, largely in anticipation of high-speed communication systems that benefit from space division multiplexing [1][2][3][4][5][6] . These activities have, in turn, incited a renewed attention in the nonlinear properties of such many-mode structures [7][8][9] aimed at establishing new platforms for high-power fiber-based light sources 10 .…”

Multimode-fiber-based single-shot full-field measurement of optical pulses

“…The spatial, temporal, spectral or polarization states of transmitted light are manipulated by shaping the spatial wavefront of an incident beam. Hence, an MMF can function as a microscope [5][6][7][8], a reconfigurable waveplate [26] or a pulse shaper [17][18][19][20]. In particular, the coupling between spatial and temporal degrees of freedom in an MMF enables tailoring the output state in time by manipulating the input state in space.…”