Abstract
We report an experimental investigation of timereversed ultrasonically encoded optical focusing in biological tissue. This technology combines the concepts of optical phase conjugation and ultrasound modulation of diffused coherent light. The ultrasonically encoded (or tagged) diffused light from a tissue sample is collected in reflection mode and interferes with a reference light in a photorefractive crystal (used as a phase conjugation mirror) to form a hologram. Then a time-reversed copy of the tagged light is generated and traces back the original trajectories to the ultrasonic focus inside the tissue sample. With our current setup, we can achieve a maximum penetration depth of 5 mm in a chicken breast sample and image optical contrasts within a tissue sample with a spatial resolution approximately equaling 1/√2 of the ultrasound focal diameter.
| Original language | English |
|---|---|
| Article number | 030506 |
| Journal | Journal of Biomedical Optics |
| Volume | 17 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1 Mar 2012 |
| Externally published | Yes |
Keywords
- Biological tissue
- Optical focusing
- Optical imaging
- Optical phase conjugation
- Photorefractive crystal
- Reflection mode
- Time reversal
- Ultrasound modulation
ASJC Scopus subject areas
- Biomedical Engineering
- Biomaterials
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics