Highly Versatile Real‐Time Optical Noise Filtering Through Temporal Cloaking

ABSTRACT Temporal cloaking has emerged as a powerful tool for hiding events in time by creating and subsequently closing temporal gaps in a probe signal. This work introduces a novel application of this concept to noise filtering of optical signals. The unique capabilities of this approach are showcased through application to a particularly challenging problem, the denoising of narrowband (MHz‐bandwidth) optical signals, overcoming crucial limitations of current optical bandpass filters and other denoising solutions. A Talbot‐based temporal cloaking system applies temporal phase modulation and group‐velocity dispersion to concentrate the coherent signal into periodic high‐intensity pulses while leaving broadband noise temporally diffuse. A selective temporal filter then transmits the signal‐bearing pulses and blocks the noise‐dominated intervals. The noise‐mitigated signal is restored by reversing the cloaking transformations, enabling effective noise suppression without loss of signal information. This approach offers electronically programmable filter bandwidths through reconfigurable Talbot phase and temporal filter profiles, and achieves optical‐domain noise filtering while preserving compatibility with downstream optical processing. The system can be specifically adapted for efficient denoising of narrowband optical signals. Remarkably, about 8 dB of additional signal‐to‐noise‐ratio improvement is achieved for residual narrowband noise after conventional optical bandpass filtering, across various MHz‐bandwidth temporal waveforms buried in noise.