Silicon nitride waveguides offer a high nonlinear refractive index and tight mode confinement, ideal for efficient four-wave mixing (FWM) processes. We present a light source for broadband as well as narrowband coherent anti-Stokes Raman scattering (CARS), with the potential to be set up as an all-integrated device, based on FWM in silicon nitride waveguides. Signal and idler pulses are generated via FWM with only 4 nJ input pulse energy and stimulated using a tunable continuous-wave seed source, such that the idler and residual pump pulses can be used for CARS measurements, enabling chemically-selective label-free imaging across the entire fingerprint region.
|