A time integrating acousto-optic correlator for residue arithmetic processing is described with experimental confirmation included. This system offers superior input and output space bandwidth product to space integrating systems described previously.Optical residue arithmetic processors have received considerable attention [1--4]. These systems are attractive because they enable arithmetic operations to be performed without carries (and hence in parallel at high rates) and at high accuracy (without the need for components with large dynamic range). Optical systems are attractive for these processors because of their large time or space-bandwidth product and parallel processing features. In this paper, we utilize a correlation formulation [2] of residue arithmetic operations. Rather than using spatial pulse-position coding [1 ] to represent decimal and residue numbers, we employ a variant we refer to as temporal pulse-position coding. We describe a time integrating correlator and demonstrate its use in decimal-to-residue conversion. This system differs considerably from prior space-integrating correlators for optical residue processing [2] and offers superior input and output space-bandwidth product performance plus allows realization with available acousto-optic transducers with high bandwidth.In residue arithmetic, an integer J is represented by the N-tuple set of remainders or residues (Rml, Rm2, ..., RmN ) with respect to the N integer moduli (M 1 , M 2 .... , MN). The maximum integer value that can be represented by the N moduli is M -1 where M = HN1 m i. It is useful background to review the correlation processing used to convert J into R m when spatial pulse position coding is used [2]. Consider a multichannel frequency plane correlator with input g(xo) = 8(x 0 -JAx), i.e. a delta function whose spatial location encodes J. Its Fourier transform G(u)is incident on the frequency plane where a square-wave grating with fundamental frequency Ug is placed. The separation between orders in the transform of the grating is chosen to satisfy max = Ug~,J'L, where fL is the focal length of the transform lens. In the output correlation plane, we obtain( 1) //Since RmdXX = U ~ nm)Zxx, we can aperture the region 0 ~