High-gain far-detuned nonlinear frequency conversion in optical fibers: intramodal vs. intermodal processes

• DOI: 10.48550/arxiv.2405.01436
• Publication Date: 2024-05-02
• Authors: Karolina Stefańska; Pierre Béjot; Julien Fatome; G. Millot; Karol Tarnowski; Bertrand Kibler
• Keywords: FOS: Physical sciences; [PHYS] Physics [physics]; Physics - Optics; Optics (physics.optics)

We present theoretical and experimental evidence of high-gain far-detuned nonlinear frequency conversion, extending towards both the visible mid-infrared, in a few-mode graded-index silica fiber pumped at 1.064 $\mu$m, more specifically achieving gains hundreds dB per meter below 0.65 $\mu$m beyond 3.5 $\mu$m. Our findings highlight potential fibers terms strong modal confinement over an ultrabroad spectral range for enabling wavelength conversion. Such advancements require accurate interpretation intramodal intermodal four-wave mixing processes.