Simulation and experimental characterization of aluminium oxide thermo-optic phase shifters for visible photonics application

Silicon photonics has become one of the most promising photonic integration platforms in the recent years. The combination of high-index-contrast and compatibility with CMOS processing technology made it possible to use the electronics fabrication facilities to make photonic circuitry. There has been a tremendous interest towards integration of photonic devices for example in the fields of life science, quantum computing and atomic physics. The ultraviolet, visible and near-infrared (250-950 nm) wavelength windows are of great interest for these kinds of applications. In the recent years, a silicon nitride photonics platform has been developed at imec for wavelengths > 500 nm, but a mature, low-loss integrated photonics technology for the 250-450 nm wavelength range is still lacking. To cover this wavelength range, imec has started investigating aluminum oxide as waveguide material for low-loss photonics applications.
 
Tunable phase shifters are key components to realize photonic devices that allow light switching, modulation or filtering. In this thesis, we will investigate thermo-optic phase shifters for the blue wavelength of 450 nm. The student will perform thermal and optical simulations to predict the insertion loss and phase shifter efficiency for different device variations. The effect of thermal isolation trenches, a full undercut and looped waveguides under the heater will be studied, to come to an optimal thermo-optical phase shifter design for the aluminum oxide waveguide technology. A 200 mm lot with many device variations will be available. The student will learn to use a fully automated photonics wafer probe station, and will electrically and optically characterize the phase shifters on full 200 mm wafer-scale. Data analysis scripts will be developed to extract key device parameters and accurately compare phase shifter performance with simulation results. Based on all simulations and experimental results, the student will design the optimal thermo-optic phase shifter device to be used in a next device fabrication run.
 
The student will gain hands-on experience with optical design, wafer-scale device characterization and data analysis of large data set. The candidate should have a strong interest in photonics, metrology and data analysis.

Type of Project: Thesis 

Master's degree: Master of Science; Master of Engineering Science; Master of Engineering Technology 

Master program: Nanoscience & Nanotechnology; Physics 

Supervisor: Pol Van Dorpe (Physics, Nano) 

For more information or application, please contact the supervising scientist Pieter Neutens (pieter.neutens@imec.be).