Supporting experimental data (5-mode-group subset) for broadband SST transmission matrix characterisation of a multimode fibre

This dataset contains Spatial State Tomography (SST) measurements of a graded-index multimode fibre, acquired for six short-coherence optical sources and analysed for 5 mode groups. The fibre supports 20 mode groups in total; because it is graded-index, an arbitrary number of mode groups can be treated as the relevant subspace, provided that higher-order modes outside the chosen set are not launched. The full (20 mode-group) dataset is available on request. Data were collected by sweeping a laser and recording 118 wavelengths (optical frequencies) spanning a 40 nm bandwidth centred at 1300 nm. The six datasets correspond to emulated source bandwidths of 0, 5, 10, 20, 30, and 40 nm, obtained by incoherent summation of the measured intensities, following the methods described in the main manuscript. A Jupyter notebook that processes this data is available at: https://github.com/MarKo7s/SST_MMF_characterization/blob/main/SST_MTM_retrival_example_experimental.ipynb Each bandwidth dataset contains horizontal (H) and vertical (V) intensity frames for each analyser state. The file measurements_specs.pkl provides the metadata used to combine these measurements in subsequent processing.