Ultra-low loss photonic circuits in Lithium Niobate On Insulator

TL;DR

This paper demonstrates ultra-low loss single-mode waveguides in Lithium Niobate on insulator, significantly improving fabrication quality and enabling advanced photonic applications in communications and quantum tech.

Contribution

It reports the fabrication of LNOI waveguides with unprecedented low propagation loss and near-vertical sidewalls, addressing previous manufacturing challenges.

Findings

Propagation loss of 0.4 dB/cm achieved

Waveguides with 75° sidewall angle demonstrated

Potential for high-efficiency photonic devices in various fields

Abstract

Lithium Niobate on insulator (LNOI) photonics promises to combine the excellent nonlinear properties of Lithium Niobate with the high complexity achievable by high contrast waveguides. However, to date, fabrication challenges have resulted in high-loss and sidewall-angled waveguides, limiting its applicability. We report LNOI single mode waveguides with ultra low propagation loss of 0.4 dB/cm and sidewall angle of 75{\deg}. Our results open the route to a highly efficient photonic platform with applications ranging from high-speed telecommunication to quantum technology.