Imaging through scattering media with holography

Depth-resolved holography through turbid media using photorefraction

“…This is a much more difficult challenge, which can in part be addressed by a time-gated coherent detection, which uses short coherence length light to provide an ultrafast time gate, thereby rejecting late arriving scattered light that arrives outside the pulse width. This technique is most effective in transillumination systems where there is no scattered light arriving before the ballistic light [19]. It is desirable, however, to use a time-gate in a retro-reflection geometry that can provide depth-resolved 3-D images by using the time of flight information.…”

Optical phase conjugation for turbidity suppression in biological samples

“…Although OPC has been used in numerous laser-related applications, such as high-resolution imaging 3 , laser resonators 4,5 and pulse compression 6 , its use in suppressing turbidity in biomedical applications has remained largely unexplored. The use of interferometric wavefront sensing and holographic techniques in biomedical optics has largely focused on phase imaging and the selection of minimally scattered light for imaging [7][8][9] . We note that there have been significant investigations of phase-conjugation techniques in the microwave and ultrasound regimes.…”

Continuous-wave ultrasonic modulation of scattered laser light to image objects in turbid media

“…The current research topics in this area include time-domain short-pulse laser imaging, [3][4][5] frequency-domain imaging, [6][7][8][9][10] and other ballistic or quasi-ballistic imaging. [11][12][13][14] The key problem with these techniques is the trade-off between imaging resolution and signal. [15][16][17] Marks et al have investigated tissue imaging by using the combination of pulsed ultrasound and laser light and have detected the signal of a homogeneous turbid medium without buried objects.…”