Use of coherent control methods through scattering biological tissue to achieve functional imaging
- Departments of *Chemistry and †Physics and Astronomy, Michigan State University, East Lansing, MI 48824
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Communicated by James L. Dye, Michigan State University, East Lansing, MI, October 18, 2004 (received for review June 30, 2004)
Abstract
We test whether coherent control methods based on ultrashort-pulse phase shaping can be applied when the laser light propagates through biological tissue. Our results demonstrate experimentally that the spectral-phase properties of shaped laser pulses optimized to achieve selective two-photon excitation survive as the laser pulses propagate through tissue. This observation is used to obtain functional images based on selective two-photon excitation of a pH-sensitive chromophore in a sample that is placed behind a slice of biological tissue. Our observation of coherent control through scattering tissue suggests possibilities in multiphoton-based imaging and photodynamic therapy.
Footnotes
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↵ ‡ To whom correspondence should be addressed. E-mail: dantus{at}msu.edu.
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Author contributions: I.P., V.V.L., and M.D. designed research; J.M.D.C. and I.P. performed research; M.C. contributed new reagents/analytic tools; J.M.D.C., I.P., M.C., and M.D. analyzed data; M.D. wrote the paper and performed overall project direction and management; and V.V.L. provided theoretical analysis and predictions.
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Abbreviations: BPS, binary phase shaping; HPTS, 8-hydroxypyrene-1,3,6-trisulfonic acid; MIIPS, multiphoton intrapulse-interference phase scan; PDT, photodynamic therapy; SHG, second harmonic generation; TL, transform-limited.
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Freely available online through the PNAS open access option.
- Copyright © 2004, The National Academy of Sciences
