Thesis Format
Monograph
Degree
Master of Engineering Science
Program
Electrical and Computer Engineering
Supervisor
Sabarinathan, Jayshri
Abstract
Inter-satellite communication is a growing industry that can drastically increase bandwidth and minimize latency in the optical communication spectrum. The current method of optical inter-satellite communication rely on bulky mechanical movements to establish a link between satellites. Using an Optical Phased Array (OPA) in silicon photonics, beamsteering can be achieved on a centimeter scale. The phase shifter is an important OPA component that requires improvement for use in space. Periodic structures such as subwavelength gratings and 2D-photonic crystals can increase the phase sensitivity of a phase shifter by slowing down the speed of light in a structure to enhance light-matter interaction. In this thesis, two main tasks are achieved. Firstly, the performance of a thermo-optic phase shifter with a subwavelength grating is evaluated through various optical and active measurements. Second, the performance of an optical-MEMS phase shifter is improved by modifying the geometry of a photonic crystal with Finite-Difference-Time-Domain simulations.
Summary for Lay Audience
The market for satellite broadband internet through use of low orbit constellations is growing, as it advertises as a method to minimize delays in communication, as well as increase the volume of data that can be sent. Optical inter-satellite communication is an extremely important method to satisfy these constraints, largely because inter-satellite communication occurs at infrared frequencies, meaning higher data rates are possible in comparison to radio frequencies.
The current method of optical inter-satellite communication relies on bulky mechanical movements to direct radiation lobes and establish a link between satellites. Instead, we can look towards established techniques in radio frequencies, where a radiation lobe can be controlled without any mechanical movements. This technique, coined beamsteering, can also be implemented in the optical domain, via an Optical Phased Array (OPA), by confining and manipulating light on a silicon chip platform that is only a few centimeters large.
We are particularly interested in the substructure of the OPA that allows the movement of a radiation lobe, the phase shifter. Phase shifters in an OPA generally have some type of actuation method applied to their silicon structure that induces a change in phase. Many different geometries of a phase shifter exist, however structures with a periodic dielectric contrast has been found to improve the performance of a phase shifter. Two main tasks are achieved in this thesis. Firstly, the performance of a temperature-actuated (thermo-optic) phase shifter with a one-dimensional periodic structure is evaluated through various optical and current measurements. Second, the performance of a displacement-actuated (optical-MEMS) phase shifter is improved by simulating different geometry modifications of a two-dimensional periodic structure.
Recommended Citation
Essington, Mackenzie, "Periodic structures to Improve Performance of Silicon based Optical Phase Shifters for Inter-Satellite Communication" (2024). Electronic Thesis and Dissertation Repository. 10454.
https://ir.lib.uwo.ca/etd/10454