The article comments on a significant breakthrough in detecting mid-infrared light at low photon counts.

The emerging discipline of picophotonics explores events on a scale thousands of times smaller than the wavelength of light. A recent work introduces a phase singularity ruler that allows picometer-scale localization metrology in three dimensions.

The commentary discusses work recently published in Physical Review Letters, which reported a nondestructive approach to realizing precise control of p-p stacking at single molecule scale by laser illumination.

The advancement of ultrafast science necessitates diagnostic techniques capable of higher precision and increased dimensionality for few-cycle pulses. As pulses continue to shorten temporally and broaden spectrally, the temporal and spatial components become inseparable. Consequently, many established techniques fall short of accurately diagnosing both the temporal and spatial characteristics of pulses. We propose an all-optical spatiotemporal oscilloscope to comprehensively characterize the waveform of few-cycle pulses. By introducing a spatiotemporal perturbing pulse to influence high-harmonic (HH) generation, the frequency of the radiating HHs oscillates with variations in the delay between the pulses. This spatially dependent frequency oscillation of the HHs enables the reconstruction of the temporal and spatial details of the perturbing pulse. This method provides a straightforward and reliable strategy for multidimensional waveform characterization of few-cycle pulses, with potential applications in probing ultrafast dynamical processes carrying spatiotemporal information.

Dense waveguides are the basic building blocks for photonic integrated circuits (PICs). Due to the rapidly increasing scale of PIC chips, high-density integration of waveguide arrays working with low crosstalk over broadband wavelength range is highly desired. However, the subwavelength regime of such structures has not been adequately explored in practice. We propose a waveguide superlattice design leveraging the artificial gauge field mechanism, corresponding to the quantum analog of field-induced n-“photon” resonances in semiconductor superlattices. This approach experimentally achieves −24 dB crosstalk suppression with an ultrabroad transmission bandwidth more than 500 nm for dual polarizations on the Si3N4 platform. The fabricated waveguide superlattices support high-speed signal transmission of 112 Gbit/s with high-fidelity signal-to-noise ratio profiles and bit error rates. This design, featuring a silica upper cladding, is compatible with standard metal back-end-of-the-line processes. Based on such a fundamental structure, which is readily transferable to other platforms, passive and active devices over versatile platforms can be realized with a significantly shrunk on-chip footprint, thus it holds great promise for significant reduction of the power consumption and cost in PICs.

Ultracompact metasurfaces have gained a high reputation for manipulating light fields precisely within a subwavelength scale, bringing great development to the fields of nanophotonics, integrated optics, and quantum technology. There is broad interest in expanding the working band of metasurfaces to expand functionalities and the scope of applications. However, increasing the number of working wavelengths multiplexed in a single holographic metasurface is always complicated by two vital issues, i.e., spectral cross talk and the efficiency imbalance between different wavelength channels. Therefore, holographic metasurfaces with multiplexed working wavelengths over three are seldom reported. To address these two issues, we present a design strategy based on unevenly distributed pixels (UEDPs). As a proof of concept, a UEDP-based metasurface is designed to offer a camouflage method to hide four encrypted holographic images in a multicolor printed image. Our results not only demonstrate the idea of UEDP as an easy-to-implement and effective way for strengthening the wavelength multiplexing of metasurfaces but also give rise to a camouflage metasurface by integrating high-capacity and high-security encrypted holographic information with a single printed image. We believe that the generic UEDP-based metasurface design strategy can be readily extended to the realization of artificial functional structures in various disciplines, such as optics, thermology, and acoustics.

This erratum notes a correction to a grant number listed in the Acknowledgments section of the originally published article.