Full recovery of ultrafast waveforms lost under noise

Abstract

The ability to detect ultrafast waveforms arising from randomly occurring events is essential to such diverse fields as bioimaging, spectroscopy, radio-astronomy, sensing and telecommunications. However, noise remains a significant challenge to recover the information carried by such waveforms, which are often too weak for detection. The key issue is that most of the undesired noise is contained within the broad frequency band of the ultrafast waveform, such that it cannot be alleviated through conventional methods. In spite of intensive research efforts, no technique can retrieve the complete description of a noise-dominated ultrafast waveform of unknown parameters. Here, we propose a signal denoising concept involving passive enhancement of the coherent content of the signal frequency spectrum, which enables the full recovery of arbitrary ultrafast waveforms buried under noise, in a real-time and single-shot fashion. We experimentally demonstrate the retrieval of picosecond-resolution waveforms that are over an order of magnitude weaker than the in-band noise. By granting access to previously undetectable information, this concept shows promise for advancing various fields dealing with weak or noise-dominated broadband waveforms.

Quantum and coherent signal transmission on a single-frequency channel via the electro-optic serrodyne technique

“…2. A comparable effect was used in demonstrating coherent denoising ( 37 , 38 ), where different coherence times were exploited to separate a coherent signal from incoherent noise.…”

Inverse Design of Photonic Systems

“…The design of such systems can be challenging (Figure 1): setups must often bridge the electrical and optical domains, achieve multi-parameter performance targets, and rely on the complex interplay of system processes, e.g., gain, loss, modulation, dispersion, interference, nonlinearity, etc. [20][21][22][23][24] As early as the 1950s, numerical approaches have been used to support photonics design, [24] ultimately evolving into today's rich ecosystem of optics simulation and optimization techniques. Nevertheless, the state-of-the-art in photonic systems often remains hampered by time-consuming design-test cycles and by the limits of human intuition, [25] especially for complex, high-dimensional design spaces.…”