Physical mode analysis of multimode cascaded nonlinear processes in strongly-coupled waveguides

• DOI: 10.48550/arxiv.2410.24073
• Publication Date: 2024-10-31
• Authors: Lisi Xia; Petrus J.M. van d...; Chris Toebes; Klaus J. Boller
• Keywords: Mode (computer interface)

We experimentally investigate on-chip control and analysis of spatially multimode nonlinear interactions in silicon nitride waveguide circuits. Using widely different dispersion transverse supermodes a strongly-coupled dual-core section, using integrated pairs input output single-mode waveguides, we enable controlled excitation processes multiple supermodes, while basic physical mode decomposition aids the identification parallel cascaded processes. Pumping with ultrashort pulses at 1.5-$\mu$m wavelength (around 195-THz light frequency), observe simultaneous dual-supermode, near-infrared supercontinuum generation having spectral widths, third-harmonic around 515 nm (582 THz). Cascaded four-wave mixing components upconverts radiation toward set four shorter blue wavelengths emitted range between 485 450 (617 to 661 The approach taken here, i.e., chip-integrated spatial multiplexing demultiplexing for broadband conversion, can be an advanced tool better understanding optics, such as extending frequency conversion wider ranges via extra phase matching paths.