| 研究実績の概要 |
The experimental setup developed in the first year of the project was first optimized, in order to improve the sensitivity of the measurements in near-infrared (800-1000 nm) to enable measurements with deeper penetration. Different tests were also performed in order to reduce the non-interfering background in the retrieved images, such as by employing various ratios between the two interfering beams, or by changing the focusing position of the object on the camera.
The two modalities (full-field OCT and Raman spectroscopy) were adjusted to enable easy transitions between the two measurement methods, and the fields of view were adjusted in order to enable joint measurement of both structural (OCT) and molecular (Raman) information.
Phantoms made of plastic beads embedded in gelatin were prepared, with both polystyrene and PMMA plastics. The use of these samples demonstrated the capability of detecting the beads locations in 3D with OCT, and then to identify the material based on their spectral response through targeted measurements in Raman. The system was also employed to perform measurements on typical test samples such as onion, which has easily identifiable layers, or ex vivo samples made of muscle tissue or skin.
Some resources were also dedicated to help develop a measurement approach based on compressed sensing, which can enable Raman imaging with much fewer measurements than usually required, potentially leading to imaging with infrared Raman excitation, despite its longer exposure time.
|
