Five dimensional information encoding using spiral phase masks in coded aperture imaging

In this study, we extend the multidimensional capabilities of interferenceless coded aperture correlation holography (I-COACH) by incorporating orbital angular momentum (OAM) as an additional encoding dimension through spiral phase masks. Unlike previous work on vortex speckles generated via self-interference of OAM beams, where OAM influenced correlation properties, here the OAM states are deterministically introduced by the system and embedded into the point-spread function (PSF), enabling their use as an independent encoding channel alongside spatial and spectral information. Through numerical simulations and optical experiments, we analyze the normalized cross-correlation of point spread functions and the quality of the reconstructed outputs for multiple spatial–spectral–OAM states. The results reveal structured correlations and reciprocity effects between axial position, wavelength, and topological charge, which govern the discrimination capability of the system. Both simulated and experimental reconstructions show strong agreement, achieving high-fidelity recovery under matching conditions while exhibiting controlled cross-talk for correlated states. These results demonstrate that OAM can be incorporated as an independently controlled encoding dimension within the I-COACH framework through system-defined PSFs. This approach enables discrimination of optical states across spatial, spectral, and OAM domains and provides a pathway toward advanced applications in optical communication, beam diagnostics, and precision metrology.