We experimentally investigate intermodal nonlinear interactions, such as Raman scattering and four wave mixing. The fiber used is a specially designed few moded fiber, which splits the degeneracy of the first mode group, leading to stable propagation of the two full vectorial modes, TM01 and TE01. For the Raman experiments pumping occur in either the fundamental mode or the two full vectorial modes, whereas the signal is in the fundamental mode. In all three experiments approximately 40 dB of gain is achieved using 307 W of pump peak power. When pumping in either of the full vectorial modes four wave mixing is observed.
Bibliographical noteThis paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-21-23-28836. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.
Rishøj, L. S., Kristensen, P., Ramachandran, S., & Rottwitt, K. (2013). Experimental demonstration of intermodal nonlinear effects between full vectorial modes in a few moded fiber. Optics Express, 21(23), 28836-28841. https://doi.org/10.1364/OE.21.028836