Abstract

We report on intra- and inter-modal four-wave-mixing (FWM) in N-fold rotationally symmetric (C_N) single- and multi-core chiral photonic crystal fiber (PCF), created by spinning the preform during fiber drawing. The non-circular modal field is forced to rotate as it propagates along the fiber, resulting in circular birefringence and robust maintenance of circular polarization state. Multi-core chiral C_N PCF supports vortex-carrying helical Bloch modes (HBMs) in which the degeneracy between clockwise and counter-clockwise vortices is lifted. This makes possible new kinds of intermodal polarization modulational instability (PMI). We develop PMI theory for vortex HBMs, and illustrate the results by a series of experiments in which two or more PMI sidebands with different vorticities and polarization states are selectively generated by adjusting the polarization state and topological charge of the pump light. In every case both the topological charge and the spin of the pump light are conserved. We also report generation of a broadband supercontinuum in a single circularly polarized vortex mode.

Cross-phase modulational instability of circularly polarized helical Bloch modes carrying optical vortices in a chiral three-core photonic crystal fiber

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Frenet–Serret analysis of helical Bloch modes in N-fold rotationally symmetric rings of coupled spiraling optical waveguides

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Polarization modulation instability in photonic crystal fibers

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Full-field characterization of helical Bloch modes guided in twisted coreless photonic crystal fiber

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Opt. Lett. 44(20) 5049-5052 (2019)

Circularly polarized guided modes in dielectrically chiral photonic crystal fiber

Junqing Li, Qiyao Su, and Yusheng Cao
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