Strong coupling between semiconductor excitons and localized surface plasmons (LSPs) giving rise to hybridized plexciton states in which energy is coherently and reversibly exchanged between the components is vital, especially in the area of quantum information processing from fundamental and practical points of view. Here, in photoluminescence spectra, rather than from common extinction or reflection measurements, we report on the direct observation of Rabi splitting of approximately 160 meV as an indication of strong coupling between excited states of CdSe/ZnS quantum dots (QDs) and LSP modes of silver nanoshells under nonresonant nanosecond pulsed laser excitation at room temperature. The strong coupling manifests itself as an anticrossing-like behavior of the two newly formed polaritons when tuning the silver nanoshell plasmon energies across the exciton line of the QDs. Further analysis substantiates the essentiality of high pump energy and collective strong coupling of many QDs with the radiative dipole mode of the metallic nanoparticles for the realization of strong coupling. Our finding opens up interesting directions for the investigation of strong coupling between LSPs and excitons from the perspective of radiative recombination under easily accessible experimental conditions.

suffer from high cost, complementary metal-oxide-semiconductor (CMOS) incompatibility, and not being environment friendly. Design and fabrication of a low-cost and CMOS-compatible siliconbased photoconductor is always urgent for current and future optoelectronics application. Unfortunately, silicon-based photoconductors usually exhibit a certain degree of latency in the photocurrent fluctuation when light is on or off, usually around 1-10 ms. [13][14][15] Meanwhile, they also suffer from a very large dark current, due to the extrinsic charge injection under reverse bias voltage, which causes the shot noise, weakens the detection sensitivity, and increases the power wastage. [12,16] Recently, the chalcogen (S, Se, and Te) and some transition metals (Au, Ti, etc.) hyperdoping in silicon has been recognized to be a potential for the fabrication of silicon-based photodetectors. [3,4,[17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] It has been reported that the chalcogen hyperdoped silicon photodetector can exhibit a high photoconductive gain under illumination while preserve a diode-rectifying effect in the dark. [24][25][26][29][30][31] This provides a novel path to the silicon-based photoconductors with a low noise and a high detect sensitivity. It was reported that the charge carrier trap states may play an essential role in the enhanced photoresponse. [24] However, this phenomenon has not yet been reported in the transition metal hyperdoped silicon photodetectors, and the related mechanism and its operating principle for this type of silicon photoconductors are still open for question. Meanwhile, theoretical calculations suggest that chalcogen dopant hyperdoping in silicon is not the best choice for the fabrication of photoconductors. [32,33] The silver (Ag) hyperdoping in silicon has a relatively higher optical figure of merit (v, defined by the ratio of carrier lifetime to transmit time), which is expected to have stronger potential in the optoelectronic application. [32,33] However, this interestingly theoretical prediction is still lack of the verification of related experiments.Here, we report a highly sensitive and room-temperature operated bulk silicon photodetector based on Ag hyperdoped silicon (Si:Ag). The Si:Ag samples were prepared by thermal evaporation deposition of Ag films and subsequent femtosecond pulsed laser melting (fs-PLM). A large density of Silicon-based photoconductors, with their low cost, high sensitivity, and complementary metal-oxide-semiconductor (CMOS) compatibility, have great potential for high-resolution imaging, light-activated switching, and singlephoton counting. However, they usually suffer from a large dark leakage current and a long response time, which greatly limits their applications. Here, a highperformance bulk silicon photodetector is fabricated working at room temperature with a broad spectral response range from 300 to 1200 nm through silver (Ag) hyperdoping. The detector shows a low dark current of 3.8 × 10 −7 A cm −2 and a high external quantum efficie...

We theoretically predict and experimentally observe the two-dimensional (2-D) bright solitons in a nonconventionally biased strontium barium niobate (SBN) crystal. A theory describing light propagating in an SBN crystal with a bias field along an arbitrary direction is formulated. Then the existence of 2-D bright solitons in such a crystal is numerically verified. By employing digital holography, the index changes induced by Gaussian beams in an SBN crystal under different biasing conditions are visualized. Finally, skewed elliptical solitons are experimentally demonstrated.

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