Abstract/Details

Pulsed optoelastic interferometric spectroscopy and imaging


2005 2005

Other formats: Order a copy

Abstract (summary)

We have developed a novel spectroscopic imaging technique based on time-resolved measurements of laser-induced thermoelastic expansion. Our system is based on a modified Mach-Zehnder interferometer that provides surface displacement measurements with a temporal resolution of 4 ns and a displacement sensitivity of 0.3 nm upon irradiation of a sample with a Q-switched Nd:YAG (λ=532 or 1064 nm, τp=5 ns) laser pulse. Such surface displacement measurements contain information regarding the spatial distribution of the absorbed energy density following laser irradiation. This can enable the recovery of the optical properties in a homogeneous sample by employing a combined light transport and thermoelastic model. Moreover, such signals can be used to generate a tomographic image of various heterogeneities through a delay-and-sum backprojection algorithm. Despite demonstrating the accuracy of the δ-P1 approximation in providing fluence distributions inside a sample following laser irradiation, the recovery of optical properties from homogeneous samples has not been successful because of limitations in the thermoelastic wave propagation model. However, imaging efforts have met with great success. We demonstrate the ability to provide 2-D and 3-D images with better than 200 μm lateral resolution and better than 30 μm axial resolution in a strongly scattering medium (μ' s=1/mm) at depths approaching 10 mm from surface displacement measurements acquired at multiple locations on the surface of tissue phantoms. Furthermore, we have been able to reconstruct tomographic images of the chicken chorio-allantoic membrane vasculature as well as that of the adult rat brain, indicating promise for our method to provide functional information in in-vivo biological systems.

Indexing (details)


Subject
Biomedical research
Classification
0541: Biomedical research
Identifier / keyword
Applied sciences; Imaging; Interferometric spectroscopy; Optoelastic
Title
Pulsed optoelastic interferometric spectroscopy and imaging
Author
Carp, Stefan Alexandru
Number of pages
181
Publication year
2005
Degree date
2005
School code
0030
Source
DAI-B 67/03, Dissertation Abstracts International
Place of publication
Ann Arbor
Country of publication
United States
ISBN
0542578301, 9780542578304
Advisor
Venugopalan, Vasan
University/institution
University of California, Irvine
University location
United States -- California
Degree
Ph.D.
Source type
Dissertations & Theses
Language
English
Document type
Dissertation/Thesis
Dissertation/thesis number
3209284
ProQuest document ID
305032436
Copyright
Database copyright ProQuest LLC; ProQuest does not claim copyright in the individual underlying works.
Document URL
http://search.proquest.com/docview/305032436
Access the complete full text

You can get the full text of this document if it is part of your institution's ProQuest subscription.

Try one of the following:

  • Connect to ProQuest through your library network and search for the document from there.
  • Request the document from your library.
  • Go to the ProQuest login page and enter a ProQuest or My Research username / password.