The polarisation of a photon is a quantum photonics workhorse for many reasons—optical devices such as waveplates and polarising beam splitters make it possible to manipulate and measure polarisation states with ease, allowing their integration into quantum information technologies.
While photonic spatial modes promise high-dimensional quantum information systems with massive information capacities and an increased robustness to noise, tools for manipulating and measuring them are far from perfect.
In our paper published today in Optics Express, we demonstrate a new technique that allows us to measure the azimuthal and radial modes of a photon using a single phase screen with greater than 99% accuracy! We expect our method will enable quantum and classical communication systems that exploit the full information-carrying potential of light.
BBQ Lab 