Phase shift module

Chemistry

Materials science

Waveguide

Optoelectronics

Optical modulator

Physics

Phase modulation

Organic chemistry

Optics

Wafer

Silicon

Birefringence

Silicon nitride

Phase (matter)

Wavelength

Phase noise

Insertion loss

Visible spectrum

Liquid crystal

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