Light-based processing and machine learning featured heavily in San Diego at the 2024 SPIE Optics + Photonics conference. Enthusiasm was coupled with questions related to the real-world applicability and the merits of linear vs non-linear, and all-optical vs hybrid, approaches.

Better ideas emerge from interactions among diverse cohorts, so scientific research benefits from contributions from everyone. Diversity in gender, race, nationality, region of the world, and other orientations is essential to create an environment in which creative thinking thrives and in which scientific discovery finds a fruitful breeding ground1. However, this is not what you see if you look at

Daniel Mittleman spoke with Nature Photonics about promising applications using terahertz waves, including spectroscopy, imaging, wireless communications, and quality control in industry.

Correction to: Nature Photonics https://doi.org/10.1038/s41566-024-01544-6, published online 18 October 2024.

The enhanced photodetector was fabricated on silicon-on-insulator substrates consisting of a 3-μm SiO2 layer and a 1.5-μm Si device layer. On top of that, an 80-nm PbSe thin film was deposited by an evaporation process. Hole arrays arranged in a square lattice were formed by ion etching. The depth of the holes was 150 nm. The Chinese scientists fabricated three devices: one without hole arrays and

Nature Photonics spoke with Hatice Altug, from the École Polytechnique Fédérale de Lausanne (EPFL), Thomas Krauss, from the University of York, and Malini Olivo from the Agency for Science, Technology and Research (A*STAR) about optical biosensors and their prospects and challenges for clinical translation.

Now, a team of scientists from Stanford University in the USA have exploited a fundamental relationship in optical physics, the Kramers–Kronig (KK) relations, in order to make the skin of a mouse transparent (see picture), allowing its internal organs to be observed (Z. Ou et al. Science https://doi.org/10.1126/science.adm6869; 2024). The KK relations mean that the wavelength dependence of the real

However, achieving a similar feat with inorganic materials, especially metals, has proved challenging owing to their properties. Now, Yaoyu Wang and co-workers from Wuhan University in China and Purdue University in the USA report how two-photon decomposition and optical force trapping can print 3D structures from metals, metal oxides and alloys, with a resolution as fine as 100 nm (Y. Wang et al.

Now, writing in Nature, Dong, Brückerhoff-Plückelmann and colleagues demonstrate that low-coherence light can, somewhat counterintuitively, be employed for photonic convolutional computing, and even enhance it (B. Dong et al. Nature 632, 55–62; 2024). The low-coherence light, produced by filtering the emission from an erbium-doped fibre amplifier, is evenly split by amplitude between N input channels