Silicon Photonic Multi-analyte Sensing System and Surface Plasmon Enhanced Chirality Detection

• Author / Creator

  Mi, Guangcan

• Optical sensing and measurement technology provides one of the most accurate tools for detecting and characterizing materials. They are robust, can provide a rich amount of information about the analytes, and are amenable to miniaturization and large-scale integration on a chip for certain applications. In this thesis, we develop novel optical sensing and measurement methods for two important applications, namely environmental greenhouse gas monitoring and chiral compound analysis for pharmaceutical and biochemical research. The first part of the thesis aims to develop an integrated multi-analyte gas sensor on a silicon photonic platform for the parallel detection of CO2 and H2 gas concentrations in the atmosphere. The development of a compact sensor that can measure CO2 gas concentrations at the atmospheric level is motivated by the need for accurate monitoring of greenhouse gas for climate change study. A key contribution of the thesis is to demonstrate a silicon photonic refractometric CO2 sensor based on a novel functional material that can be integrated with other gas sensors on the same chip. A prototype dual-gas sensor chip based on a wavelength-multiplexed microring array was also developed for the simultaneous detection of CO2 and H2 gases. Gas sensing experiments were conducted to evaluate the performance of each sensor in the presence of other analytes, and to address important issues related to multi-analyte sensing environment such as cross-sensitivity. The results obtained and knowledge gained from the study help lay the groundwork for future development of multi-analyte sensor systems on a chip for monitoring greenhouse gases and industrial emissions. The second part of thesis aims to develop novel ellipsometric methods for measuring the chirality of biochemical compounds. In particular we explore the unique properties of chiral surface plasmon polaritons for enhancing the detection sensitivity of these methods. The research is motivated by the important role of chirality in governing the biological functionalities of biochemical compounds. Measurement of chirality provides information about molecule conformation, enantiomeric purity or excess, and chiral compound concentrations, which are important in pharmaceutical research and other biomedical fields. The ellipsometric methods developed could offer crucial advantages over existing techniques in terms of accuracy, small sample size and the ability to measure multiple optical quantities in the same setup. In addition, chiral surface plasmon waveguide structures investigated offer promising solutions for realizing chiral sensors on an integrated platform.

• Subjects / Keywords

  • Surface Plasmon
  • Photonic Sensor
  • Silicon Photonics
  • Chirality

• Graduation date

  Spring 2017

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R30Z7183M

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.