Published: February 01, 2018
Daniel D. Hickstein, Grace Kerber, David R. Carlson, Lin Chang, Daron A. Westly, Kartik A. Srinivasan, Abijith S. Kowligy, John Bowers, Scott A. Diddams, Scott B. Papp
Supercontinuum generation in on-chip waveguides is a versatile source of broadband light and the generated spectrum is determined by the phase-matching conditions. Here we show that quasi- phase-matching via periodic modulations of the waveguide structure provides additional control over the spatial mode and spectrum of the supercontinuum. We experimentally demonstrate that a sinusoidal width modulation of a silicon nitride waveguide provides quasi-phase-matched dispersive wave generation to the TE20 mode. Additionally, we show that a periodic presence of SiO2 under-cladding can provide numerous quasi-phase-matched dispersive waves to both the TE20 and TE00 modes through higher-order grating effects, up to the 16th grating order. This quasi- phase-matching scheme adds a new dimension to the design-space for photonic-chip supercontinuum sources, and could enable new light sources that can be precisely engineered for specific applications.
Citation: Physical Review Letters
Pub Type: Journals
frequency combs, lasers, nonlinear optics, photonic devices, supercontinuum generation
Created February 01, 2018, Updated March 26, 2018