Optomechanical transduction harnesses the interaction between optical fields and mechanical motion to achieve sensitive measurement of weak mechanical quantities with inherently low noise. Lithium niobate combines low optical loss, strong piezoelectricity, a high intrinsic f × Qm factor, and low thermal conductivity, making it promising for exploring optomechanical platforms targeting thermal sensing applications. Here, we demonstrate an integrated optomechanical platform on thin-film lithium niobate with precisely engineered optical, mechanical, and thermal fields within a compact 40 μm-diameter footprint. The platform integrates suspended microring resonators with ultrathin central membranes, reducing effective mass and thermal capacitance while maintaining a high intrinsic optical quality factor Qo of 106 and a mechanical quality factor Qm of 1117, which increases to 5.1 × 104 upon optomechanical oscillation. The two-step etching suppresses thermal dissipation into the silicon substrate and enhances thermal sensitivity, achieving a temperature coefficient of frequency of −124 ppm K−1, a measurable loaded thermal response time of 7.2 μs, and a noise-equivalent power of 6.2 nW Hz−1/2 at 10 kHz and room temperature. This compact and scalable platform opens new opportunities for high-sensitivity thermal sensing and power detection and supports heterogeneous integration with infrared absorbers for uncooled infrared detection, thereby paving the way toward large-format infrared sensing arrays with low-noise, all-optical readout.
Abstract Metasurfaces are considered the backbone of the ongoing photonics revolution to shape the electromagnetic waves on demand via a flat array of resonators. The beauty of metasurfaces lies in their ability to simultaneously control multiple waves. However, obtaining such multi-functionality often requires active components, such as active electronics and complex tuning mechanisms. A recent study demonstrates a fully passive architecture, composed of sliding metasurfaces that combines two distinct functionalities, i.e. frequency-selective filtering with wide-angle beam steering in a single platform. By replacing local phase reconfiguration with a simple geometric translation between complementary phase profiles, the work introduces a simple yet innovative route to a two-dimensional frequency-angle selection window. It opens new opportunities for passive wave-based information processing.
As the thermal backbone of urban energy infrastructure, transmission cables directly affect the stability and resilience of modern cities. However, high operating temperatures, driven by Joule heating and solar radiation, critically limit the ampacity of overhead transmission lines, particularly under extreme climate conditions. Such high temperatures constrain electricity delivery and pose systemic risks to essential services and long-term urban sustainability. To overcome this challenge, we adopt a high thermal conductivity radiative cooling (HTCRC) coating comprising hexagonal boron nitride (h-BN) nanoparticles embedded in a polydimethylsiloxane matrix to reduce cable temperature. Enabled by photonic thermal management, this composite structure simultaneously achieves high solar reflectance (0.92) through efficient light scattering, strong mid-infrared emissivity via polymer vibrational modes (0.95), and enhanced thermal conductivity (1.28 W m⁻¹ K⁻¹). Outdoor experiments demonstrate notable daytime cooling of simulated HTCRC-coated power cables, maintaining safe operating temperatures even under intense solar exposure. In addition, thermal modeling based on the CIGRE 601 standard reveals a 6–10% increase in ampacity across representative hot-climate cities globally. These findings highlight high thermal conductivity radiative cooling as an effective and scalable strategy to enhance urban power grid performance, improve energy delivery security, and support the development of climate-resilient cities under rapidly growing electricity demand driven by electrification and the expanding energy footprint of artificial intelligence.
Abstract Accessing the rich information carried by infrared light typically relies on bulky, complex optoelectronic systems. Lanthanide-based upconverting nanoparticles (UCNPs) offer a compelling alternative by converting infrared light into visible photons through nonlinear anti-Stokes processes. However, achieving strong upconversion under the low excitation intensities relevant to infrared vision remains challenging, motivating strategies to enhance light–matter interaction. Here, we demonstrate enhanced infrared-to-visible upconversion imaging enabled by integrating alloyed Yb/Er UCNPs with a resonant dielectric metasurface. The metasurface supports an optical resonance aligned with the UCNP excitation band, leading to over three orders of magnitude enhancement in upconversion emission. Crucially, flat-band angular dispersion of this resonance enables uniform enhancement across incident angles relevant to imaging, thereby preserving spatial frequency content and yielding sharp, high-contrast images. In light of ongoing advances in lanthanide-based materials, this metasurface–UCNP hybrid screen provides a promising platform for compact, detector-free, and scalable infrared imaging technologies based on optical upconversion.
Abstract Plasmon–exciton Fano interference provides an efficient channel for coherent energy transfer, and the plasmon resonance energy transfer (PRET) peak is usually observed around the Fano dip at the exciton resonance. In this work, we achieve tunable multiple Fano interferences and multichannel PRET by strategically coupling five excitonic resonances (labeled as M, D h , D j , H, and J) of assembled IR806 molecules with Au nanobipyramids and nanorods (AuNBPs and AuNRs, respectively). Notably, owing to orientation-dependent molecule–plasmon coupling in the IR806/AuNBP hybrids, we observe two PRET peaks with opposite signs of Fano factor $$q$$ q . One PRET peak remains fixed near the J-aggregate exciton resonance at ~900 nm, whereas the other is located around the plasmon resonance and tuned from 710 to 920 nm. The total PRET reaches a maximum when the two PRET peaks are tuned into spectral overlap. Furthermore, our newly developed semiclassical model quantitatively reproduces these features, which reveals that PRET enhancement arises from the superposition of multiple Fano interferences. These findings provide a novel strategy to enhance the efficiency and tunability of the PRET, opening avenues for advanced applications in ultrafast optical information processing and highly sensitive photodetectors.
