Open AccessMulti-exposure interferometric diffusing wave spectroscopy
Author(s) -
Wenjun Zhou,
Mingjun Zhao,
Oybek Kholiqov,
Vivek J. Srinivasan
Publication year - 2021
Publication title -
optics letters/optics index
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.524
H-Index - 272
eISSN - 1071-2763
pISSN - 0146-9592
DOI - 10.1364/ol.427746
Subject(s) - optics , interferometry , spectroscopy , speckle pattern , materials science , speckle imaging , detector , physics , quantum mechanics
We present multi-exposure interferometric diffusing wave spectroscopy (MiDWS), which measures brain blood flow index (BFI) continuously and non-invasively. MiDWS employs interferometry to detect low light levels, probing the optical field autocorrelation indirectly by varying the sensor exposure time. Here MiDWS is compared with conventional interferometric diffusing wave spectroscopy and speckle contrast optical spectroscopy in phantoms. Notably, the MiDWS approach enables the use of low frame rate, two-dimensional complementary metal-oxide semiconductor cameras in a short exposure time regime, where detector noise greatly exceeds the sample photon count. Finally, we show that MiDWS can monitor the BFI simultaneously at two source-collector separations (1 and 3 cm) on the adult human head on a single camera, enabling the use of superficial signal regression techniques to improve brain specificity.