Day 1: Seeing Order in Disorder
David Norris
The application of adaptive optics techniques--namely, optical wavefront shaping and phase modulation--to correct aberrations arising from highly scattering and disordered media holds tremendous promise for in vivo fluorescence imaging of biological tissue, and in particular the functional imaging of neural circuits. This topic has experienced an explosion of research activity in recent years, driven in large part by funding and interest from the BRAIN initiative, the Presidential focus aimed at mapping and unlocking the inner workings of the human brain. Following previous Incubator meetings in Optogenetics and Adaptive Optics, the organizers see today’s meeting as a natural next step.
Most of the new techniques take a hybrid acousto-optic approach to imaging, using a high numerical aperture ultrasound transducer to focus deep inside tissue and a spatial light modulator to tailor an excitation pulse into sharp focus in the same region. The latter has now been accomplished through a variety of strategies, such as phase conjugation, optimization of photoacoustic feedback, and measurement of the system transmission matrix. The organizers hope that this two-day meeting will allow participants to compare notes on which techniques work best under which conditions (e.g. ballistic versus diffusive scattering), which seem most promising for high-speed imaging in vivo, and what technology bottlenecks still need to be overcome in order to make these techniques viable for widespread use.
