Short-Wave InfraRed or SWIR imaging utilizes the region of the electromagnetic spectrum from approximately 1.4μm to 3.0μm which lies well outside the sensitivity window of the eye, and that of silicon photodetectors. This region of the spectrum can exhibit reduced scattering due to tissue, and hence is useful for imaging deeper into organs such as the brain.
Many of the problems of working in the infrared are just practical; finding detectors, fluorophores, optics and sources that work in the desired spectral bands can be difficult, so much of our work in this field involves finding analagous components to those available in the visible region of the electromagnetic spectrum.
One recent project involved the use of quantum dot fluorophores to track blood flow in a mouse brain. Quantum dots were injected and used to image deep below the brain's surface, and by applying a maximum intensity projection, 3D localization information could be obtained. Using particle tracking velocimetry code developed in the Rowlands lab, these flows could be quantified and mapped.