Search

Arterial walls are vital for vascular function and disease, but their complex mechanics are not fully understood. Using broadband optical coherence elastography, the authors find that tissue viscoelasticity decreases with stretch, and collagen fibers are key for the adventitia’s nonlinear stiffening and overall nonlinear viscoelasticity.

Mammalian and bacteria cells producing fluorescent proteins (FP) have been recently proposed as living sources of laser light. Here, Gather and Yun demonstrate efficient lasing in the solid state form of FPs and observed Förster resonance energy transfer between molecules in blends of different FPs.

A metal–semiconductor structure as small as 170 nm in diameter emits lasing light from the lowest-order plasmonic mode across a broad spectral range in the infrared.

Scientists demonstrate living biological lasers by pumping cells containing green fluorescent protein in a highly reflective microcavity. The researchers also investigate the thresholds and modes of their cellular lasers.

Here, Brillouin optical microscopy noninvasively visualizes microscale anisotropy of the porcine cornea owing to its lamellar fiber structure and quantifies the longitudinal moduli of the bulk tissue. Anisotropy is also detected in angle-resolved measurement of the human cornea in vivo.

Barcoding individual cells with microparticles emitting near-infrared laser light enables the use of flow cytometry for the measurement of time-resolved single-cell dynamics with more markers and fewer colours.

Understanding the mechanical properties of materials is critical in many fields, from soft hydrogels to biological tissues, yet current measurement methods lack the spatial and time resolution to characterize samples with complex structures. Here, the authors show non-invasive elastography technique offering advancements in resolution, sensitivity, and measurement frequencies.

Reconfigurable materials are of interest for many photonic applications. Here, Montelongo et al. demonstrate optical elements such as Bragg diffraction gratings, volumetric photonic crystals, lenses, and holograms in a composite with dispersed nanoparticles which can be recorded and erased.

Light-based therapies are of growing importance in medicine, though penetrating tissue and reaching the targeted area can be difficult. Here, the authors report the use of biodegradable waveguides capable of directing light where desired, and demonstrate the potential for wound healing.

Intracellular laser particles based on silica-coated semiconductor microcavities with distinct emission wavelengths allow real-time tracking of thousands of cells in a tumour model.

Spectral reflectance has been used to achieve label-free, in vivo imaging of myelin, a membranous sheath that allows faster electrical conduction along neuronal axons. Here the authors extend this technique to measure nanoscale features, including changes following traumatic brain injury.

Polymer hydrogel patches that are capable of supporting living cells and guiding light are used to perform in-vivo optical sensing and therapy in living mice. Tasks performed include toxicity testing and glucose regulation.

Needle-sized photonic devices that slowly dissolve in the body can spectroscopically characterize cerebral temperature, blood oxygenation and neural activity for weeks in unconstrained mice.

Brillouin scattering microscopy is prone to artefacts and inconsistencies. This Consensus statement provides recommendations for measuring and reporting relevant parameters with the aim of standardizing protocols and improving the comparability of studies.

Measuring the in-plane mechanical stress in a taut membrane is challenging, but fundamental to basic research and practical applications, from engineering to tissues. Here, the authors propose an accurate measurement technique of the in-plane stress in thin films based on the speed of elastic waves measured through optical coherence tomography, and demonstrate it on a rubber membrane, common household plastic wrap, and leather skin of an Irish frame drum.

Brillouin microscopy can be used to analyze the mechanical properties of cells in a contact-free fashion. Cells in 2D and 3D environments are accessible to this technology, which provides measurements of longitudinal moduli at optical resolution.

A combinatorial approach using laser particles for optical barcoding enables distinguishing thousands to millions of cells. Theoretical framework and enhanced tagging pave the way for scalable single-cell tracking and analysis.

Optofluidic biolasers are emerging as a highly sensitive way to measure changes in biological molecules. Biolasers, which incorporate biological material into the gain medium and contain an optical cavity in a fluidic environment, take advantage of the amplification that occurs during laser generation to quantify tiny changes in biological processes in the gain medium. This Perspective describes the principle of the optofluidic biolaser, reviews recent progress and provides outlooks on potential applications and directions for developing this enabling technology.

This Review provides a broad account of the applications of light in imaging, diagnosis, therapy and surgery, and discusses the promise of emerging light-based technologies.