Bragg Soliton Compression and Fission on CMOS‐Compatible Ultra‐Silicon‐Rich Nitride
Higher‐order soliton dynamics, specifically soliton compression and fission, underpin crucial applications in ultrafast optics, communications, and signal processing. Bragg solitons exploit the strong dispersive properties of periodic media near the photonic band edge. This enables soliton dynamics to occur in very short propagation distances, opening avenues to harness soliton compression and fission in integrated photonic platforms. However, implementation in complementary metal‐oxide semiconductor (CMOS)‐compatible platforms has been hindered by the strong nonlinear loss that dominates the propagation in silicon and the low‐optical nonlinearity of traditional silicon nitride. Here, CMOS‐compatible, on‐chip Bragg solitons, are presented with a soliton‐effect pulse compression with a factor of × 5.7, along with time‐resolved measurements of soliton fission on a CMOS‐compatible photonic circuit platform. These observations are enabled by the combination of a unique cladding‐modulated Bragg grating design and the high nonlinearity and negligible nonlinear loss of compositionally engineered ultra‐silicon‐rich nitride (USRN: Si7N3).