High thermo-optic tunability in PECVD silicon-rich amorphous silicon carbide

In this work, the thermo-optic coefficient (TOC) of the silicon-rich amorphous silicon carbide (a-SiC) thin film deposited by plasma-enhanced chemical vapor deposition (PECVD) was characterized. We found that the TOC of the film increases as its silicon content increases. A more than threefold improvement in the TOC was measured, reaching a TOC as high as 1.88 x 10-4 degrees C-1, which is comparable to that of crystalline silicon. An efficient thermo-optic phase shifter has also been demonstrated by integrating the silicon-rich a-SiC micro-ring structure with a NiCr heater. Tunability of 0.117 nm/mW was demonstrated, and a corresponding tuning efficiency P pi as low as 4.2 mW has been measured at an optical wavelength of 1550 nm. These findings make silicon-rich a-SiC a good candidate material for thermo-optic applications in photonic integrated circuits.(c) 2023 Optica Publishing Group

Automated summary

The thermo-optic coefficient (TOC) of silicon-rich amorphous silicon carbide (a-SiC) thin film deposited by plasma-enhanced chemical vapor deposition (PECVD) was characterized in this work. It was found that the TOC increases with the silicon content of the film. The TOC showed a more than threefold improvement, reaching a value as high as 1.88 x 10-4 degrees C-1, comparable to crystalline silicon. An efficient thermo-optic phase shifter was demonstrated by integrating the silicon-rich a-SiC micro-ring structure with a NiCr heater, achieving a tunability of 0.117 nm/mW and a tuning efficiency P pi as low as 4.2 mW at an optical wavelength of 1550 nm. These findings suggest silicon-rich a-SiC as a promising material for thermo-optic applications in photonic integrated circuits.