Volume holographic correlator allows simultaneously calculate the two-dimensional inner product between the input
image and each stored image. We have recently experimentally implemented in VHC 4000 parallel correlation channels
with better than 98% output accuracy in a single location in a crystal. The speckle modulation is used to suppress the
sidelobes of the correlation patterns, allowing more correlation spots to be contained in the output plane. A modified
exposure schedule is designed to ensure the hologram in each channel with unity diffraction efficiency. In this schedule,
a restricted coefficient was introduced into the original exposure schedule to solve the problem that the sensitivity and
time constant of the crystal will change as a time function when in high-capacity storage. An interleaving method is
proposed to improve the output accuracy. By unifying the distribution of the input and stored image patterns without
changing the inner products between them, this method could eliminate the impact of correlation pattern variety on
calculated inner product values. Moreover, by using this method, the maximum correlation spot size is reduced, which
decreases the required minimum safe clearance between neighboring spots in the output plane, allowing more spots to be
parallely detected without crosstalk. The experimental results are given and analyzed.
In order to overcome the resolution limits of the detector array to the spectrometer, the super-resolution algorithms is adopted. On the basis of the study on the integral and sampling property of the detector array, the spectral line adaptability to the super-resolution algorithms was verified. The algorithms were tested respectively by three classic spectral line profiles - Gaussian, Lorentzian and Voigt, and the deviation of the reconstructed spectral line and the original one was analyzed. Consequently, the super-resolution algorithm and its optimal parameter for different spectral line profiles were deduced.