Imaging the Reflection Phase of Nanophotonic Structures

Many groups worldwide study nanophotonic structures with sensitive (position-resolved) intensity reflectivity, to successfully investigate advanced systems like plasmonic systems, innovative sensors, non-linear photonics, coupled-cavity superlattices, see e.g. [1]–[3]. In most work, intensity information is collected, hence the absolute square of the reflected fields <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\vert E_{r}\vert^{2}$</tex>. If it is feasible to obtain information of the complex reflected field <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$E_{r}$</tex>, one accesses a wealth of new information. This serves imaging purposes, like optical coherence tomography (OCT) [4], [5], or more info on complex behaviour of waves scattered in intricate nanophotonic structures, including mesoscopic reflection matrices, see e.g. [4]–[6]. Notably, position-resolved phase yields access to optical matrices with a position input basis to enhance OCT imaging depth [4], [5].