Silicon nitride

Phase shift module

Phase (matter)

Materials science

Optical modulator

Silicon

Wavelength

Phase noise

Visible spectrum

Insertion loss

Physics

Organic chemistry

Waveguide

Optics

Electro-optic modulator

Wafer

Phase modulation

Chemistry

Liquid crystal

Birefringence

Optoelectronics

Optics Express

In this work, an integrated liquid-crystal-based phase modulator operating at visible wavelengths was developed and experimentally demonstrated. A visible-light silicon-nitride-based 300-mm-wafer foundry platform and a liquid-crystal integration process were developed to leverage the birefringence of liquid crystal to actively tune the effective index of a section of silicon-nitride waveguide and induce a phase shift over its length. The device was experimentally shown to achieve a 41π phase shift within 4.8 Vpp for a 500-µm-long modulator, which means that a 2π phase shifter would need to be only 24.4 µm long. This device is a compact and low-power solution to the challenge of integrated phase modulation in silicon nitride and paves the way for future low-power small-form-factor integrated systems at visible wavelengths.

Integrated visible-light liquid-crystal-based phase modulators