Chemically synthesized metal nanowires are promising building blocks for next-generation photonic integrated circuits, but technological implementation in monolithic integration will be severely hampered by the lack of controllable and precise manipulation approaches, due to the strong adhesion of nanowires to substrates in non-liquid environments. Here, we demonstrate this obstacle can be removed by our proposed earthworm-like peristaltic crawling motion mechanism, based on the synergistic expansion, friction, and contraction in plasmon-driven metal nanowires in non-liquid environments. The evanescently excited surface plasmon greatly enhances the heating effect in metal nanowires, thereby generating surface acoustic waves to drive the nanowires crawling along silica microfibres. Advantages include sub-nanometer positioning accuracy, low actuation power, and self-parallel parking. We further demonstrate on-chip manipulations including transporting, positioning, orientation, and sorting, with on-situ operation, high selectivity, and great versatility. Our work paves the way to realize full co-integration of various functionalized photonic components on single chips.

Although monolayer transition metal dichalcogenides (TMDs) have direct bandgaps, the low room-temperature photoluminescence quantum yields (QYs), especially under high pump intensity, limit their practical applications. Here, we use a simple photoactivation method to enhance the room-temperature QYs of monolayer MoS₂ grown on to silica micro/nanofibers by more than two orders of magnitude in a wide pump dynamic range. The high-density oxygen dangling bonds released from the tapered micro/nanofiber surface are the key to this strong enhancement of QYs. As the pump intensity increases from 10⁻¹ to 10⁴ W cm⁻², our photoactivated monolayer MoS₂ exhibits QYs from ~30 to 1% while maintaining high environmental stability, allowing direct lasing with greatly reduced thresholds down to 5 W cm⁻². Our strategy can be extended to other TMDs and offers a solution to the most challenging problem toward the realization of efficient and stable light emitters at room temperature based on these atomically thin materials.

Implementing compact, efficient, and reliable passive pulsed lasers at visible wavelengths is attractive. This paper systematically investigated the thickness-dependent optical absorption characteristics of two-dimensional materials, including graphene, transition-metal dichalcogenides, and dye films at the 532 nm wavelength band, and revealed the effects of thickness on different optical absorption parameters. The results suggested that dye films are more suitable for loss-sensitive pulsed lasers and graphene is more suitable for modulation depth-sensitive pulsed lasers, while transition-metal dichalcogenide samples have intermediate performance. It can provide guidance for the rational selection of saturable absorbers in pulsed all-fiber lasers to optimize the optical pulse performance in the visible-wavelength band.

Experimental near‐field analysis of the output beams from the end faces of micro/nano‐waveguide is very necessary, because important information such as spatial intensity distributions, mode orders, and divergence angles can be obtained, and are very important for investigating and designing nanophotonic devices. However, as far as we know, it has not been demonstrated yet. In this work, we experimentally demonstrate a plasmonic‐nanowire near‐field beam analyzer, utilizing a single Au nanowire (AuNW) as the probe to scan the spatial near‐field distributions of emitted beams from micro/nano‐waveguide end‐faces. Our analyzer can resolve the trade‐off between high measurement resolution and light collection efficiency in conventional beam analyzers by a reverse nanofocusing process, achieving a probe resolution of 190 nm (< λ /8) and a simulated collection efficiency of ∼47.4 % at λ = 1596 nm. These attractive advantages allow us to obtain three‐dimensional (3D) scanning in a large range from the plasmonic hotspot region to the far‐field region, characterizing the 3D spatial distribution evolution from a metal nanowire output beam for the first time, with an M ² factor lower than that of the ideal Gaussian beam ( M ² = 1). In addition, the analyzer also demonstrates simultaneous characterization of multimodes in irregular and large‐sized nanoribbons, further verifying its ability to selectively explore complex multimodes that are difficult to be predicted by numerical simulations. Our results suggest that this plasmonic‐nanowire beam analyzer may hold promise for diverse near‐field applications for micro/nano‐waveguides such as nanolasers and biosensing, and offer a new method for understanding nanophotonic structures.

This paper proposes a multichannel optimal squeezing-displacement receiver (MOSDR) with photon-number-resolving detectors for discriminating binary phase-shift keying (BPSK) coherent states. Unlike previous squeezing-based receivers whose gain is largely limited to the low photon-number regime, we partition the input signal into multiple channels so that the mean photon number in each channel is reduced, allowing the squeezing operation to be used more effectively in its favorable operating region. In addition, we use displacement feedforward between channels and accumulate the per-channel discrimination outcomes through a sequential decision process, thereby reducing the overall error probability. We analyze MOSDR under an ideal detector as well as under quantum efficiency, dark counts and visibility reduction. The results show that MOSDR outperforms an optimized-displacement multichannel displacement feedforward receiver and remains below the standard quantum limit over a wide photon-number range, exhibiting improved robustness to detection imperfections.

The sine carrier is widely used to realize the modulation for the information in many fields like electrical communication and scientific measurement. Specifically in high-precision measurements, a sine carrier endowed with ultrahigh amplitude stability is of paramount importance. In this brief, based on direct digital synthesis (DDS), a sine carrier generator is introduced with a stepwise-approximated sine wave (SASW) being band-pass filtered. Through the joint optimization of multiple parameters, a novel theoretical approach is investigated for improving the fundamental amplitude stability (FAS) of the SASW. Finally, a simulation utilizing a self-multiplying evaluation system model is performed and the simulation results verify the theory well.