Spatial mode demultiplexing for super-resolved source parameter estimation

We present the use of a multi-planar light converter (MPLC) to perform spatial mode demultiplexing (SPADE) for optical source parameter estimation. This technique has been extended to use higher-order Hermite-Gaussian modes for the purposes of estimating the separation of a pair of incoherent sources, both above and below the diffraction limit. We resolve these sources at separations 90× lower than the diffraction limit. We also show our system is capable of simultaneous separation estimation and relative power estimation while maintaining super-resolving capabilities, with relative power differences as large as 20 dB by using the additional information gained by incorporation of the higher order modes. These results support the potential use of SPADE for astronomical imaging of binary systems.