Abstract: In a control system, with a defined clock rate C—a method and apparatus for generating a train of pulses whose mean level is proportional to a given number V, having N equispaced possible values, the pulses to be applied to a given low-pass process, the method comprising generating a train of constant-amplitude pulses at a rate that is considerably greater than C/N, when the width of each pulse is an integer multiple of a clock period, 1/C, and the widths of all pulses are not necessarily equal.

Abstract: An optical address decoder, and an associated method for routing optical data packets. One embodiment of the decoder includes a plurality of waveguides, and semireflective elements that define, within each waveguide, a resonant cavity, each resonant cavity being of a different length. Addresses are encoded as equal spacings of sequences of optical pulses. An address to be decoded is directed simultaneously to all waveguides. Resonance is set up only in the waveguide whose resonant cavity matches the optical pulse spacing of the address. Another embodiment of the decoder includes a plurality of waveguides of different lengths, with the length difference between adjacent waveguides corresponding to a certain propagation time interval. Each waveguide terminates in an optoelectronic detector. Addresses are encoded as patterns of bits spaced according to this propagation time interval, with optical pulses representing "1" bits. An address to be decoded is directed, bit by bit, simultaneously to all waveguides.