Wideband Spectral Enhancement through On-Chip Bragg-Soliton Dynamics

The generation of supercontinuum provides high-brightness, spectrally-rich light needed for hyperspectral imaging, broadband spectroscopy and fluorescence microscopy. Soliton-fission based supercontinuum generation typically requires high powers and femtosecond pulse pumping to occur. Here, we demonstrate the enhancement of supercontinuum generation using a monolithically integrated, CMOS-compatible device to induce soliton fission in a cladding modulated Bragg grating, via Bragg soliton dynamics for picosecond pulses. Subsequent propagation in the monolithically integrated channel waveguides leads to 4.3× enhancement in the spectral content of the output compared to a reference waveguide of the same length. A similar enhancement is observed when compared to launching the pulses far from the grating band edge, outside of the Bragg soliton regime. We generate 340 nm wide supercontinuum using a 1.7 ps input pulse at a peak power of 5.5 W.