A Novel Thermo-Optic Phase Shifter Based on Anti-Symmetric Bragg Grating

Thermooptic phase shifter (TOPS) plays an important role in the silicon photonics integrated circuits. In this article, we proposed and experimentally demonstrated a novel TOPS based on the anti-symmetric Bragg grating (ASBG). By using the ASBG and anti-directional coupler, the overlap integral of light field and thermal field is increased by three times. The TOPS has been fabricated on CUMEC's standard CSiP180Al and CSiP130Cu silicon photonics platform. The experimental results show that the efficiency of the TOPS is about
$6.75\text{mW}/\pi$
, which is only about a third of the conventional TOPS. At the same time, the rise time and drop time are only 7.1
$\mu\mathrm{s}$
and 9.7
$\mu\mathrm{s}$
. The proposed TOPS based on the ASBG paves the way for a high efficiency TOPS for the silicon photonics integrated circuits without sacrificing the switching time.