Shedding light on untapped information in photons
Conventional optical imaging systems today largely limit themselves to the measurement of light intensity, providing two-dimensional renderings of three-dimensional scenes and ignoring significant amounts of additional information that may be carried by captured light. For example, many photons traverse complex paths punctuated by multiple bounces prior to entering the aperture of a camera or other imager—a process through which these photons pick up information about their surroundings. Beyond such directional variability, light enjoys other aspects or degrees of freedom—including variations in propagation time, polarization state and spectral content, as well as wave-related properties such as coherence, diffraction and interference—all of which provide potential mechanisms by which light can acquire and convey information. Most of this information remains untapped today.