Optical signal processors based on a time-spectrum convolution

We show that a fiber-optics architecture conventionally used for microwave photonic filtering can implement a time-spectrum convolution (TSC) process of general interest for a wide range of fundamental optical signal processing and analysis operations. This process is practically implemented by temporally modulating a specially filtered broadband incoherent light source followed by propagation through a suitable linear dispersive medium. The TSC concept allows the time-domain realization of fundamental analog processing operations over both temporal and spectral intensity waveforms. Three particular, relevant signal-processing operations are proposed and experimentally demonstrated here to illustrate the broad potential of application of the TSC concept, namely time-integration, spectrum-integration, and time-frequency correlation of discrete binary codes.