Design of a Curved Shape Photonic Crystal Taper for Highly Efficient Mode Coupling

Sensors

Gerald Stocker¹  Thomas Grille¹  Bernhard Jakoby²  Reyhaneh Jannesari²  Andreas Tortschanoff³  Cristina Consani³ 

[1] Infineon Technologies Austria AG, 9500 Villach, Austria;Institute for Microelectronics and Microsensors, Johannes Kepler University, 4040 Linz, Austria;Silicon Austria Labs GmbH, Europastraße 12, 9524 Villach, Austria;

关键词: integrated optic;    photonic crystal waveguide;    taper;    mid infrared;    non-linear taper;    curve shape taper;   

DOI  :  10.3390/s21020585

来源: DOAJ

【 摘 要 】

The design and modeling of a curved shape photonic crystal taper consisting of Si rods integrated with a photonic crystal waveguide are presented. The waveguide is composed of a hexagonal lattice of Si rods and optimized for CO₂ sensing based on absorption spectroscopy. We investigated two different approaches to design a taper for a photonic crystal waveguide in a hexagonal lattice of silicon rods. For the first approach (type 1), the taper consists of a square lattice taper followed by a lattice composed of a smooth transition from a square to a hexagonal lattice. In the second approach (type 2), the taper consists of a distorted hexagonal lattice. Different shapes, such as convex, concave, and linear, for the curvature of the taper were considered and investigated. The structure of the taper was improved to enhance the coupling efficiency up to 96% at a short taper length of 25 lattice periods. The finite-difference time-domain (FDTD) technique was used to study the transmission spectrum and the group index. The study proves the improvement of coupling using a curved shape taper. Controlling the group index along the taper could be further improved to enhance the coupling efficiency in a wider spectral range.

【 授权许可】

Unknown