Open AccessStudy of the Local Oxidation of Silicon Waveguide for Realizing the Intra-Guided Mode Conversions
Author(s) -
Ting Yu,
Bin Wang,
DeGui Sun
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1584/1/012048
Subject(s) - silicon on insulator , waveguide , materials science , silicon , silicon photonics , optoelectronics , photonics , coupling (piping) , coupling loss , optics , optical fiber , composite material , physics
The impressive achievements in research and developments of silicon-on-insulator (SOI) based silicon photonic integrated (PIC) devices have been made, but the coupling loss between the fibre and SOI waveguide is still a fatal problem. As well known, the butt coupling between a fibre and a low index-contrast silica-on-silicon (SOS) waveguide only causes a much lower optical loss, however, such a process between a fibre and a high index-contrast SOI waveguide creates a much higher optical loss. In this work, a 2-step intra-guide mode conversion of fibre-SOS-SOI structure is modelled and studied, in which a mitigating structure of SOS waveguide is created via a local oxidation of silicon (LOCOS) technique. The LOCOS method is an in-situ chemical process during the waveguides are fabricated without causing any extra fabrication, but it can control the physical parameters of the SOS waveguide through a chemical process. In such a 2-step intra-guide mode conversion, the total optical efficiency of the fibre-SOS-SOI structure is modelled, and the optical efficiencies of both the fibre-SOS mode conversion and the SOS-SOI mode conversion are systematically studied, and the broad dependences of guided mode profile on the chemical parameters of the LOCOS process are discussed. As a result, a total optical loss of <0.5dB for a butt coupling process between fibre and single-mode SOI-waveguide is achieved. So far, no similar practical butt-coupling method has been reported yet.