| Numéro |
J. Phys. IV France
Volume 04, Numéro C7, Juillet 1994
8th International Topical Meeting on Photoacoustic and Photothermal Phenomena8 ITMP3 / 8éme conférence internationale de photoacoustique et photothermique |
|
|---|---|---|
| Page(s) | C7-43 - C7-46 | |
| DOI | https://doi.org/10.1051/jp4:1994711 | |
8th International Topical Meeting on Photoacoustic and Photothermal Phenomena
8 ITMP3 / 8éme conférence internationale de photoacoustique et photothermique
J. Phys. IV France 04 (1994) C7-43-C7-46
DOI: 10.1051/jp4:1994711
1 Department of Physics, University College Swansea, University of Wales, Singleton Park, Swansea SA2 8PP, U.K.
2 Department of Aeronautics and Astronautics, University of Southampton
© EDP Sciences 1994
8 ITMP3 / 8éme conférence internationale de photoacoustique et photothermique
J. Phys. IV France 04 (1994) C7-43-C7-46
DOI: 10.1051/jp4:1994711
A differential photoacoustic imaging system
C.A. Hall1, A.W. Williams1 and N.J. Wood21 Department of Physics, University College Swansea, University of Wales, Singleton Park, Swansea SA2 8PP, U.K.
2 Department of Aeronautics and Astronautics, University of Southampton
Abstract
We describe a differential photoacoustic (PA) imaging system in which almost equal intensity beams modulated 180° out of phase illuminate two regions of a sample in a PA cell. For two regions that are both optically and thermally similar and also homogeneous, the resulting signal is almost zero but if one region has a sub-surface defect this will give an increased signal. This differential signal has a much higher signal to noise ratio than conventional PA systems.
© EDP Sciences 1994