An integrated optical system for comparing one set of voltage signals to a reference set will be described. The processor utilizes a hologram written in an outdiffused LiNb03 waveguide to effectively subtract the input signal voltage set from one or many reference sets as a means of pattern recognition. Parallel processing in a one-dimensional format should make possible comparison rates of 100 MHz for data sets containing as many as 100 information channels. The envisioned system contains the following components: A end-fired laser, a metallized-photoresist grating beam splitter and two polished-edge mirrors to form an integrated interferometer, a waveguide hologram in the area of beam recombination, and a lens to project the processed beam onto a butt-coupled detector. In the reference arm of the interferometer, a simple electrode pair is utilized to generate the phase shift required for holographic subtraction, while in the signal arm, a more complicated N-channel electrode structure is employed to electrooptically convert voltage information to spatial phase information on the guided wave. Efforts to build and characterize a three-channel system with integrated beam splitter, mirror, electrodes, and hologram are presented.