Passive Optical Limiting in Long Timescales

Open Access
Author:
Stinger, Michael Vincent
Graduate Program:
Electrical Engineering
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
June 22, 2010
Committee Members:
  • Iam Choon Khoo, Dissertation Advisor
  • Iam Choon Khoo, Committee Chair
  • Jun Huang, Committee Member
  • Timothy Joseph Kane, Committee Member
  • Zhiwen Liu, Committee Member
Keywords:
  • thermal lensing
  • long timescale
  • all-optical
  • passive
  • optical limiting
  • cavitation
  • scattering
Abstract:
From its use in medicine to measure and/or probe various physiologies to commercial applications such as data storage on optical disks, the laser has positively contributed to the lives of people around the globe. Alongside it’s unique properties, the control of laser light poses significant challenges. Optical limiting, or the truncation of optical energy at particular thresholds represents one such challenge. Given the plethora of radiation sources available, it is of significant value to identify a means by which optical limiting can be achieved simultaneously for a wide berth of source parameters. That said, this document focuses on the exploration of a particular optical limiting modality applied to long timescales; That is- optical pulses with durations on the order of hundreds of nanoseconds, microseconds and up to continuous-wave. Given that this modality has been previously shown to be broadband and effective in short timescales, evidence of it’s efficacy in long timescales would demonstrate the modality as an exceptional option in the design of truly robust optical limiting devices. The results of L34 optical limiting trials with incident laser light at a 750nm wavelength and pulse durations in the microsecond and nanosecond regimes as well as continuous-wave light at 532nm are shown and discussed. Results are discussed for both bulk and liquid-infiltrated capillary-array arrangements and for various output light collection configurations. The mechanisms by which limiting action occurs are discussed and their optimization within various configurations is considered. Through measurement in a variety of experimental situations and device configurations, the organic liquid L34 is shown to be an effective optical limiting material in long timescales. These results provide evidence that L34 is an excellent candidate for inclusion in a spectrally and temporally robust optical limiting system that is easy to construct and maintain.