Tapered air-core Bragg waveguide spectrometers for fluorescence detection in lab-on-a-chip devices

  • Author / Creator
    Drobot, Brian A
  • This thesis describes a study on tapered air-core Bragg waveguides for use as integrated micro-spectrometers in lab-on-a-chip systems. Position-dependent cutoff of the leaky waveguide modes results in spatial dispersion of polychromatic input light. These devices may be viewed as side-coupled Fabry-Perot cavities of varying core thickness. Chip-scale spectrometers have a number of applications, including point-of-care diagnostics, biochemistry, and field-deployable threat detectors. Bragg cladding mirrors with an omnidirectional band (for TE-polarized light) between ~490 nm and ~570 nm were deposited using both e-beam evaporation and reactive sputtering. Using these claddings, tapered hollow Bragg waveguides were assembled using two different methods: buckling self-assembly and a wafer-bonding process. The tapers exhibited resolutions ranging from ~2.2 nm to ~0.8 nm, for mode orders m = 1 to m = 8. Implementing the tapers in a prototype sensing system, the fluorescence spectra of individual fluorescent beads were successfully measured over the ~70 nm wide operating range of the device.

  • Subjects / Keywords
  • Graduation date
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • 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.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
    • Department of Electrical and Computer Engineering
  • Specialization
    • Microsystems and Nanodevices
  • Supervisor / co-supervisor and their department(s)
    • DeCorby, Ray (Electrical & Computer Engineering)
  • Examining committee members and their departments
    • Zemp, Roger (Electrical & Computer Engineering)
    • Tsui, Ying (Electrical & Computer Engineering)
    • DeCorby, Ray (Electrical & Computer Engineering)