Real-time all-optical overlapping time-lens array through nonlinear interference

The space–time duality is a foundational principle in modern optical signal processing, enabling temporal analogues of spatial imaging systems. Among the key components in such systems are time-lenses, whose versatility remains limited when they are arranged in arrays. Yet such configurations are essential for enabling high-resolution, gap-free optical spectral analysis and photonic waveform generation, among other demanding applications. In this work, we introduce an overlapping time-lens array (oTLA) that exploits nonlinear interference via both degenerate and non-degenerate four-wave mixing. This configuration breaks the strict trade-off between aperture length and repetition rate inherent of conventional approaches. As a result, the oTLA enables the simultaneous achievement of high time-bandwidth products—beyond several thousand—along with high repetition rate and complete and redundant temporal coverage of the input optical signal, ensuring truly gap-free operation. We showcase the capabilities of the oTLA with overlapping factors greater than 4 and a real-time optical spectrum analysis scheme offering an analysis bandwidth of 400 GHz. This proposal open new avenues for FWM-based temporal imaging systems in applications demanding seamless processing, such as ultrafast spectroscopy, high-speed telecommunications, quantum optics, and full-field measurement of broadband optical signals.