Collection |

Sensing at the limit

In this collection we highlight the latest progress in our ability to sense and image the world around us. Using principles from quantum and optical physics, access to regimes beyond the limit of our own senses has proven vital for a broad range of applications. From the nanoscale to astronomical measurements, this collection aims to represent the breadth of sensing applications and provide an outlook for future research.

Nanoscale

Tautomerization, the interconversion between two constitutional isomers of a molecule, plays a major role in chemistry. The combination of hyper-resolved fluorescence microscopy with time-correlated measurements and spectral selection enables the identification and in-depth characterization of a tautomerization reaction within a single molecular switch.

Letter | | Nature Nanotechnology

Remote Sensing

THz dual comb spectroscopy may be performed using down-converted or quantum cascade laser systems, forcing a choice between absolute frequency referencing and high sensitivity. Here, these strengths are combined in a hybrid, dual frequency comb spectrometer, capable of high-accuracy measurements on molecular transitions.

Article | Open Access | | Communications Physics

Ultrafast

Using a femtosecond mode-locked laser and a frequency-locked electric signal, a displacement measurement method that offers a >MHz measurement speed, sub-nanometre precision and a measurement range of more than several millimetres is achieved, facilitating the study of broadband, transient and nonlinear mechanical dynamics in real time.

Letter | | Nature Photonics

External stimuli can induce significant changes in the magnetisation of a material; however, these changes can occur very rapidly, making measurements difficult. Herein the authors demonstrate a method of ultrafast magnetometry, enabling the detection of the rapid magnetization changes.

Article | Open Access | | Nature Communications

Biomedical Applications

Optical microscopy is limited to shallow in vivo imaging depths owing to the exponential extinction of single-scattered waves by multiple light scattering. In this Review, we survey methodologies for deep optical imaging that maintain microscopic resolution by making deterministic use of multiple-scattered waves.

Review Article | | Nature Reviews Physics

Imaging methods in microscopy seek to simultaneously optimize spatial resolution, contrast and imaging speed even in large specimen. Here, a combination of holographic phase shaping, fluorophores-switching, and dynamic blocking of fluorescence is used to improve resolution, sectioning and imaging depth in light-sheet microscopy.

Article | Open Access | | Communications Physics