Phase modulators in hybrid silicon and lithium niobate thin films

The hybridization of mono-crystalline silicon and lithium niobate thin films (SiLNOI) can combine the physical properties of Si and the optical properties of LN, and it has emerged as a new material platform for integrated photonics. In this paper, phase modulators in Si-LNOI were demonstrated. First, the phase modulator was designed. According to the simulation, the Si loading strip waveguide had a small mode area due to the large refractive index of Si. This allowed a small electrode gap that resulted in enhancement of the overlap of the optical field and the electrostatic field, and the V pi L of the phase modulator could be as small as 3.3 Vmiddotcm. Second, phase modulators with a Si loading strip waveguide with a top width of 0.5 mu m were fabricated by plasma etching, and the V pi L of the phase modulator was measured to be 4.74 Vmiddotcm. This study provides useful information for the devices in the Si-LNOI. (C) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement