Researchers propose a new tomography scheme for reconstructing highly multimode quantum states of light using time-domain quadrature correlation measurements. The method uses dual-pulse homodyne detection with time-delayed local oscillator pulses shorter than the quantum state being measured. Unlike traditional eight-port homodyne detection, this approach obtains distinguishable mode structure through post-processing via orthogonalization of correlation data. The number of reconstructable modes scales with the number of time delays used and inversely with the local oscillator's temporal extent. The work demonstrates reconstruction of Gaussian states and opens pathways to non-Gaussian state tomography, with applications in quantum cryptography and quantum information processing.
