Tunable diode laser trace gas detection with a vertical cavity surface emitting laser

• Author / Creator

  Vujanic, Dragan

• The nature of work conducted during the course of study towards a MSc degree focused on tunable diode laser absorption spectroscopy (TDLAS). This field involves the in-situ detection of gas constituents from low concentration samples. Specifically, I will focus on TDLAS systems utilizing practical optics, readymade electronics, and commercially available near infrared vertical cavity surface emitting lasers (VCSEL). In attempting to lower the minimum detectable concentrations of constituent gases, quantifying contributory noise sources is vital. Consequently, I seek to characterize principle noise sources of a prototypical TDLAS system in order to gain understanding of the limits that inhibit detection of trace gas concentrations. The noise sources which were focused on can be categorized as follows: source laser noise, optical noise, and detection noise. Through this work it was my goal to provide the means of achieving superior sensitivities.

• Subjects / Keywords

  • Tunable diode laser absorption spectroscopy
  • TDLAS
  • BTJ-VCSEL
  • VCSEL
  • feedback operation
  • second harmonic wavelength modulation spectroscopy
  • WMS

• Graduation date

  Fall 2009

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3D33R

• 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.