Description
- Abstract:
- The photoacoustic effect, also frequently called the optoacoustic effect, was discovered by Alexander G. Bell in 1880. The effect refers to the generation of acoustic waves by absorption of optical radiation. There are numerous applications of photoacoustic effects, the most important being trace gas detection and optoacoustic tomography, which combines the advantages of strong contrast by optical absorption with deep acoustic penetration depth. Owing to these two features, the photoacoustic effect offers unique diagnostic opportunities relative to traditional imaging modalities. The thesis focuses on the generation of photoacoustic effect, detection of acoustic waves by optical deflection, and solving inverse problems in photoacoustic imaging. Chapter 1 introduces forward and inverse problems in photoacoustic imaging. In Chapter 2, the frequency and time domain features for the photoacoustic waves generated within a spherical droplet are investigated for two cases: a sphere with a surrounding region of fluid that absorbs radiation and a sphere that absorbs radiation itself. An amplification of the phoacoustic effect is found for the pressure waves generated by an oscillating optical source in a one-dimensional oscillator with potential applications in trace gas detection. Chapter 3 presents a new pressure field detection scheme using optical deflection with the goal to overcome signal distortion and low sensitivity limitations of conventional solid transducers in detecting photoacoustic waves. Chapter 4 incorporates recent developments in deep generative models and compressive sensing to mitigate some challenges confronting optoacoustic tomography. Chapter 5 discusses X-ray phase contrast imaging which is another imaging modality distinct from, but complementary photoacoustic imaging.
- Notes:
- Thesis (Ph. D.)--Brown University, 2022
Citation
Yan, Xingchi,
"Photoacoustic Effect from Droplets to Imaging"
(2022).
Chemistry Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://repository.library.brown.edu/studio/item/bdr:bzhfa922/
