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Emulsions, particularly in the pharmaceutical, cosmetic, and food industries, are essential for the delivery and stabilization of active ingredients. Due to their structural complexity—including variations in droplet size, phase distribution, and interfacial properties—characterizing emulsions is essential for optimizing their performance and stability. Existing reviews tend to focus on specific emulsion types, properties, or individual characterization techniques, often failing to provide a holistic assessment. Consequently, there is a critical need for a comprehensive review that integrates various characterization methods. This review addresses this gap by systematically evaluating key techniques, including scattering methods (dynamic light scattering, small-angle x-ray scattering), spectroscopic techniques (Fourier transform infrared and nuclear magnetic resonance spectroscopy), microscopy methods (scanning electron microscopy, confocal laser scanning microscopy), and rheometry. By consolidating the strengths and limitations of each method, this review offers a unified framework to guide researchers in selecting appropriate techniques for characterizing emulsions, ultimately contributing to the optimization of their structure, properties, and performance across diverse applications.

Abstract Nanowires are promising platforms for realizing ultra-compact light sources for photonic integrated circuits. In contrast to impressive progress on light confinement and stimulated emission in III-V and II-VI semiconductor nanowires, there has been no experimental demonstration showing the potential to achieve strong cavity effects in a bottom-up grown single group-IV nanowire, which is a prerequisite for realizing silicon-compatible infrared nanolasers. Herein, we address this limitation and present an experimental observation of cavity-enhanced strong photoluminescence from a single Ge/GeSn core/shell nanowire. A sufficiently large Sn content ( ~ 10 at%) in the GeSn shell leads to a direct bandgap gain medium, allowing a strong reduction in material loss upon optical pumping. Efficient optical confinement in a single nanowire enables many round trips of emitted photons between two facets of a nanowire, achieving a narrow width of 3.3 nm. Our demonstration opens new possibilities for ultrasmall on-chip light sources towards realizing photonic-integrated circuits in the underexplored range of short-wave infrared (SWIR).

Abstract The technology to develop a large number of identical coherent light sources on an integrated photonics platform holds the key to the realization of scalable optical and quantum photonic circuits. Herein, a scalable technique is presented to produce identical on‐chip lasers by dynamically controlled strain engineering. By using localized laser annealing that can control the strain in the laser gain medium, the emission wavelengths of several GeSn one‐dimensional photonic crystal nanobeam lasers are precisely matched whose initial emission wavelengths are significantly varied. The method changes the GeSn crystal structure in a region far away from the gain medium by inducing Sn segregation in a dynamically controllable manner, enabling the emission wavelength tuning of more than 10 nm without degrading the laser emission properties such as intensity and linewidth. The authors believe that the work presents a new possibility to scale up the number of identical light sources for the realization of large‐scale photonic‐integrated circuits.