On-chip arbitrary dispersion engineering with deep photonic networks

We demonstrate the design and optimization of on-chip arbitrary dispersion profiles using deep photonic networks constructed from custom-designed Mach-Zehnder interferometers. These photonic networks employ optimizable waveguide tapers, enabling precise engineering of wavelength-dependent dispersion profiles. We experimentally demonstrate a proof-of-concept two-port photonic network that exhibits a highly nonintuitive triangular dispersion profile over the wavelength range of 1.54 $\mu\mathrm{m}$ to 1.58 $\mu\mathrm{m}$ while simultaneously achieving a flat-band transmission with an insertion loss of less than 0.7 dB. We also illustrate the potential of multi-port photonic networks to enhance design freedom for more complex and customizable dispersion profiles, enabling new possibilities for on-chip dispersion engineering.