Implementation of the photonic time-stretch concept using an incoherent pulsed light source.

Abstract

We propose a new technique to realize photonic time stretching of radio-frequency (RF) signals by using a time-gated (pulsed) incoherent-light source. The proposed system provides similar performance specifications (stretch factor, temporal aperture, and resolution) to those of a conventional coherent system but using a temporal gating process that is significantly longer than the transform-limited pulse duration of the equivalent coherent configuration. We experimentally demonstrate temporal magnification and compression of high-speed RF signals, with time-stretch factors ranging from 0.65 to 8.66, using a broadband (11.6nm) incoherent-light source temporally gated over ∼163 ps. In one of the reported experiments, we achieve a resolution of ∼67.5 ps over a temporal aperture of ∼23 ns, representing a time-bandwidth product of >340.