Ultrafast ghost imaging with 25 GHz speckle switching and wavelength-division multiplexing

Ghost imaging (GI) and single-pixel imaging (SPI) enable image reconstruction without spatially resolved detectors, offering access to broad spectral ranges and challenging imaging environments. However, their adoption has been fundamentally limited by the slow switching of mask patterns, which constrains achievable frame rates. Here, we demonstrate ultrafast GI enabled by 25 GHz speckle pattern switching, achieving a spatial-temporal information flux exceeding 15.68 gigapixels per second, which is over two orders of magnitude higher than previous training-data-free GI approaches. By incorporating wavelength-division multiplexing (WDM), we further scale the throughput via parallelized illumination. The WDM-based GI approach is capable of reconstructing 28×28-pixel images with a 10 ns exposure time, corresponding to 100 megaframes per second (Mfps), and captures microsecond-scale dynamic events. This approach opens avenues for studying rapid processes, where conventional cameras are limited by detector bandwidth, readout speed, or cost.