An Ultra-Fast Temporal Talbot Array Illuminator

We propose an all-optical temporal Talbot array illuminator (T-TAI) enabling denoising passive amplification of broadband (
$>$
10 GHz-bandwidth) optical signals. The key element is an ultra-fast temporal phase grating based on cross-phase modulation. Whereas previous implementations of the T-TAI suffer from the bandwidth limitations inherent to electro-optic systems, the all-optical nature of the proposed approach allows to simultaneously realize high amplification factors and sampling rates, which in turn allows for the efficient processing of broadband signals. In our experiments, we demonstrate a (signal bandwidth) × (amplification factor) product exceeding 370 GHz, more than an order of magnitude improvement as compared with previous electro-optic implementations. We show the prospects of the proposed approach through the recovery of noisy high-speed optical waveforms, namely a
$\sim$
10 Gbps data signal buried in a much stronger noise background. Additionally, we experimentally demonstrate that the T-TAI samples preserve the full complex information (amplitude and phase) of the incoming signal. The proposed approach should prove useful in multiple fields requiring the detection of weak and noisy broadband signals as well as for other related applications, such as photonics-assisted analog-to-digital conversion.