## Abstract

Broadband and ultra-low crosstalk integrated silicon superlattice waveguides are proposed and demonstrated, enabling high-density waveguide integration. The superlattice waveguides are implemented as S-shaped adiabatic bends that yield ultra-low crosstalks in the neighboring channels, and an extremely low insertion loss, for the TE polarization. Special materials or complex fabrication steps are not required. The bent superlattice waveguides are measured to have an average insertion loss <inline-formula><tex-math notation="LaTeX">$\leq 0.1 \rm{dB}$</tex-math></inline-formula> for all channels. The average crosstalk values are <inline-formula><tex-math notation="LaTeX">$\leq -37.8 \rm{dB}$</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">$\leq -45.2 \rm{dB}$</tex-math></inline-formula>, in the first nearest neighboring waveguide and the second nearest neighboring waveguide, respectively. The transmission spectra are measured over the wavelength ranges of (<inline-formula><tex-math notation="LaTeX">$1.24 \mu \rm{m}$</tex-math></inline-formula> to <inline-formula><tex-math notation="LaTeX">$1.38 \mu \rm{m}$</tex-math></inline-formula>) and (<inline-formula><tex-math notation="LaTeX">$1.45 \mu \rm{m}$</tex-math></inline-formula> to <inline-formula><tex-math notation="LaTeX">$1.65 \mu \rm{m}$</tex-math></inline-formula>), covering both communication wavelengths of <inline-formula><tex-math notation="LaTeX">$1310$</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">$1550\, \rm{nm}$</tex-math></inline-formula>. The simulation results predict an efficient broadband performance over the <inline-formula><tex-math notation="LaTeX">$500\, \rm{nm}$</tex-math></inline-formula> wavelength range (<inline-formula><tex-math notation="LaTeX">$1200\, \rm{nm}$</tex-math></inline-formula> to <inline-formula><tex-math notation="LaTeX">$1700\, \rm{nm}$</tex-math></inline-formula>), covering all O, E, S, C, L & U bands. The proof of concept was done for a silicon-on-insulator platform and the approach is applicable to other waveguide geometries and integrated photonic platforms.

Original language | English (US) |
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Pages (from-to) | 1-9 |

Number of pages | 9 |

Journal | IEEE Journal of Selected Topics in Quantum Electronics |

DOIs | |

State | Accepted/In press - 2023 |

## Keywords

- adiabatic
- Bending
- Crosstalk
- Insertion loss
- Optical device fabrication
- Optical waveguides
- optical waveguides
- Silicon Photonics
- Silicon-on-insulator
- silicon-on-insulator
- superlattices
- transverse electric
- Waveguide junctions

## ASJC Scopus subject areas

- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering