Optical parametric amplification in silicon nitride waveguides for coherent Raman imaging

We present tunable waveguide-based optical parametric amplification by four-wave mixing (FWM) in silicon nitride waveguides, with the potential to be set up as an all-integrated device, for narrowband coherent anti-Stokes Raman scattering (CARS) imaging. Signal and idler pulses are generated via FWM with only 3 nJ pump pulse energy and stimulated by using only 4mW of a continuous-wave seed source, resulting in a 35 dB enhancement of the idler spectral power density in comparison to spontaneous FWM. By using waveguides with different widths and tuning the wavelength of the signal wave seed, idler wavelengths covering the spectral region from 1.1 mu m up to 1.6 mu m can be generated. The versatility of the chip-based FWM light source is demonstrated by acquiring CARS images. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

Tunable waveguide-based optical parametric amplification by four-wave mixing (FWM) in silicon nitride waveguides is presented, showing the potential for generating signal and idler pulses with different wavelengths for CARS imaging.