Phase-Noise-Insensitive Orthogonality Verification of Single-Photon-Level Temporal Modes

Photonic quantum technologies are a rapidly developing field. We seek new ways for storing more information in a single photon. One of the promising ways for multidimensional storage is using temporal modes of single photons (either time-bin or structured modes such as Hermitte-Gaussian modes) enabling us to send more information per photon using their theoretically unlimited dimensionality [1], [2]. Moreover, temporal modes offer high stability, ease of detection and creation.