Open AccessOptimization of thermo-optic phase-shifter design and mitigation of thermal crosstalk on the SOI platform
Author(s) -
Maxime Jacques,
Alireza Samani,
Eslam El-Fiky,
David Patel,
Zhenping Xing,
David V. Plant
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.010456
Subject(s) - silicon on insulator , materials science , optoelectronics , fabrication , tin , phase shift module , thermal , photonics , silicon photonics , silicon , optics , electronic engineering , insertion loss , engineering , medicine , alternative medicine , physics , pathology , meteorology , metallurgy
We first optimize the design and compare the performance of thermo-optic phase-shifters based on TiN metal and N ++ doped silicon, in the same SOI process. The designs don't require special material processing, show negligible loss, and have very stable power consumption. The optimum TiN design has a switching powerP π =21.4 mW and a time constantτ=5.6 µs, whereasP π =22.8 mW andτ=2.2 µs for the best N ++ Si design, enabling 2.5x faster switching compared to the metal heater. Doped-Si-based heaters are therefore the most practical and efficient on standard SOI. In addition, to optimize the layout density of highly integrated dies, we experimentally characterize internal and external thermal crosstalk for tunable Mach-Zehnder interferometers (MZIs) based on both heater designs for various power, distances, and etching patterns. Deep trenches are the best structures not involving special fabrication techniques to mitigate heat leakage affecting phase-sensitive devices close to heaters. Given the numerous applications of thermal tuners, this work is relevant to almost all silicon photonics designers.