High framerate, InGaAs camera for interferometric diffuse correlation spectroscopy (iDCS) beyond the water peak

Performance optimisation of a holographic Fourier domain diffuse correlation spectroscopy instrument

“…We propose to remove any spatiotemporally correlated experimental noise sources that may exist within this dataset using the SVD approach [ 32 – 34 ] that was introduced in Section 2.2 . is formed from 501 camera plane holograms, each of spatial dimensions pixels.…”

“…Within the context of multispeckle interferometric DCS, a similar approach has also recently been presented by Robinson et al [ 34 ]. These authors suggested that the largest singular values are also associated with movement artefacts and fluctuations in laser power, although the precise identity of the noise source is less important than the removal of a component of the measured data that is overly represented across the camera sensor, and which is therefore not due to the signal of an individual speckle.…”

Interferometric diffuse optics: recent advances and future outlook

“…2 )? Here we describe three potential solutions, not mutually exclusive, that are being investigated: first, enhancing SNR by further increasing the speckle number, based on parallelizing multiple cameras for iDWS/MiDWS, is a straightforward way to achieve larger S–C separation (i.e., higher brain specificity); second, combining iDWS with coherence gating, to filter out extracerebral photons with short TOFs at a small S–C separation, can improve both SNR (more cerebral photons) and brain specificity; 39 , 41 , 43 third, the intrinsic advantages of SNR and high source power for DCS at 1064 nm can be carried over to interferometric detection, 61 , 62 in which extremely costly 1064 nm photon counting detectors 63 can be replaced by InGaAs cameras, 64 which are less costly.…”

“…Indeed, we have found that a lower temporal coherence, characteristic of lower cost sources, can actually be helpful to reducing the impact of unwanted system reflections in iDWS. Finally, although iDWS at 1064 nm can also reduce the laser source cost, 64 InGaAs sensors unfortunately are expensive. Though not strictly a limitation, we project that lowering the light source cost, perhaps in conjunction with noise mitigation strategies, 47 will be important to enabling new applications in the coming years.…”