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

  • Micro-spectrometer
  • Lab-on-a-chip
  • Fluorescence detection
  • Bragg waveguide

• Graduation date

  Spring 2014

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3W08WQ80

• 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.