Work

Low-Loss Silicon Nitride Bent Waveguides at O-Band with Modified Hermite Curves

Year: 2026

Type: article

Abstract: The silicon nitride (SiN) platform offers a low-loss solution for photonic integrated circuits (PICs). The bent waveguide represents one of the primary sources of propagation loss in such integrated systems. In this work, we present a comprehensive review of recent advances in SiN bent waveguide technologies. We propose a low-loss SiN bent waveguide design integrated with modified Hermite curves. We adopt a waveguide geometry of 800 nm × 300 nm in the simulations, with the material refractive index derived from the LPCVD process. Simulations conducted at a wavelength of 1311 nm reveal that the proposed bends exhibit bending losses of 0.076 dB, 0.021 dB, 0.0055 dB, and 0.0012 dB per 90° bend, corresponding to bending radii of 15 μm, 20 μm, 25 μm, and 30 μm, respectively. Furthermore, the fabrication tolerance and wavelength dependence of the proposed design are systematically investigated to verify its practical applicability.

Source: Photonics

DOI: 10.3390/photonics13020175

Authors: Donghao Li, Enge Zhang, Yi Xu, Lei Zhang, Yu Zhang, Xu Yang

Institutions: Beijing University of Posts and Telecommunications, China Electronics Technology Group Corporation

Language: English

Topic: Photonic and Optical Devices

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,896

Funders: National Natural Science Foundation of China, Beijing University of Posts and Telecommunications, Natural Science Foundation of Beijing Municipality, State Key Laboratory of Information Photonics and Optical Communications