- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Flexible engineering of light emission in monolayer MoS <sub/>2</sub> via direct laser writing for multimode optical recording
摘要： Direct laser writing has been proved to be capable for effective modulation of optical and electrical properties of various nanomaterials. In this work, we designed a flexible direct laser writing approach to engineer photoluminescence (PL) properties of monolayer MoS2 and present its potential application in optical recording. PL spectra evolution of monolayer MoS2 under continuous-wave laser writing has been explored, where its PL energy can be precisely controlled by changing the writing time. This feature enables a multimode optical recording with spectral contrast in monolayer limit materials for high-capacity data storage technologies. Here, we constructed a proof-of-principle multimode optical recording on monolayer MoS2 based on the PL wavelength division multiplexing scheme and discussed the relevant challenges for practical applications. Our flexible approach with a mask-free feature and high spatial resolution is promising for applications in two-dimensional material-based information storage and optoelectronic devices.
关键词： direct laser writing,photoluminescence,monolayer MoS2,wavelength division multiplexing,optical recording
更新于2025-09-23 15:21:01
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Experimental and clinical study of simultaneous dual-wavelength laser action in energetic cataract surgery
摘要： A new technique of energy cataract surgery with the simultaneous use of two wave-length of laser emission acting as high-intensity laser—endodissector (Nd:YAG, wave-length λ = 1.44? μm) and a low-intensity laser—endobiostimulator (He–Ne, wavelength λ = 0.632? μm) is represented. The surgical technique is bimanual. The radiation of high-intensity laser ensures the destruction of cataract lens of any density level without addi-tional assistance of ultrasound and without manual fragmentation. The laser tip, which contacts the eye tissues, does not heat up. In the process of high-intensity laser action split-ting and spalling of the eye lens core occurs. Laser energy does not go beyond the lens capsule as it is almost completely absorbed by the liquid of the anterior chamber (water) at less than 1?mm from the distal end of the laser tip. Simultaneous exposure to radiation of high-intensity and low-intensity lasers delivered to the eye lens via one laser tip provide to prevent the progression of posttraumatic inflammatory process in the eye at the initial stage of the start of pathophysiological intracellular changes. This ensures high efficiency and safety of simultaneous dual-wavelength laser cataract extraction (DW LCE).
关键词： 0.632?μm He–Ne laser,Phacoemulsification,1.44?μm Nd:YAG laser,Dual-wavelength laser cataract extraction,Intraoperative endoocular bio-stimulation
更新于2025-09-23 15:21:01
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Ultrabroadband Photodetectors up to 10.6 ?μm Based on 2D Fe <sub/>3</sub> O <sub/>4</sub> Nanosheets
摘要： The ultrabroadband spectrum detection from ultraviolet (UV) to long-wavelength infrared (LWIR) is promising for diversified optoelectronic applications of imaging, sensing, and communication. However, the current LWIR-detecting devices suffer from low photoresponsivity, high cost, and cryogenic environment. Herein, a high-performance ultrabroadband photodetector is demonstrated with detecting range from UV to LWIR based on air-stable non-layered ultrathin Fe3O4 nanosheets synthesized via a space-confined chemical vapor deposition (CVD) method. Ultrahigh photoresponsivity (R) of 561.2 A W?1, external quantum efficiency (EQE) of 6.6 × 103%, and detectivity (D*) of 7.42 × 108 Jones are achieved at the wavelength of 10.6 μm. The multi-mechanism synergistic effect of photoconductive effect and bolometric effect demonstrates the high sensitivity for light with any light intensities. The outstanding device performance and complementary mixing photo response mechanisms open up new potential applications of nonlayered 2D materials for future infrared optoelectronic devices.
关键词： long-wavelength infrared,photoconductive effect,ultrabroadband photodetectors,bolometric effect,Fe3O4 nanosheets
更新于2025-09-23 15:21:01
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Multilayer dielectric coated Fabry Perot spectral beam combiner for high power, narrowband, widely tunable laser applications
摘要： Spectral beam combination of tunable laser beams demonstrated, using a multilayer dielectric coated single cavity Fabry Perot (FP) filter. A stack of 19 layers using TiO2 and SiO2 was optimally designed and fabricated using an electron beam evaporation technique. This filter was characterized for transmission spectrum, surface morphology and laser induced damage threshold. The sharp transmission spectrum facilitated the spectral combination of closer wavelengths (< 10 nm) around 632.8 nm. This filter was utilized as an efficient spectral beam combiner as well as an amplified spontaneous emission (ASE) filter for the transmitting wavelength. This study finds direct application for tunable, multi-wavelength laser-based differential absorption lidar (DIAL) and atmospheric remote sensing applications. The application of this device was successfully demonstrated to spectrally combine high power, tunable copper vapor laser pumped dye laser beams. A mechanism to tune the FP transmission profile along with laser beam tunability was established.
关键词： Fabry Perot beam combiner,Widely tunable laser,Amplified spontaneous emission filtering,Angle tuning mechanism,Closer wavelength spectral beam combination
更新于2025-09-23 15:21:01
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Tunable topological charge vortex microlaser
摘要： The orbital angular momentum (OAM) intrinsically carried by vortex light beams holds a promise for multidimensional high-capacity data multiplexing, meeting the ever-increasing demands for information. Development of a dynamically tunable OAM light source is a critical step in the realization of OAM modulation and multiplexing. By harnessing the properties of total momentum conservation, spin-orbit interaction, and optical non-Hermitian symmetry breaking, we demonstrate an OAM-tunable vortex microlaser, providing chiral light states of variable topological charges at a single telecommunication wavelength. The scheme of the non–Hermitian-controlled chiral light emission at room temperature can be further scaled up for simultaneous multivortex emissions in a flexible manner. Our work provides a route for the development of the next generation of multidimensional OAM-spin-wavelength division multiplexing technology.
关键词： data multiplexing,orbital angular momentum,chiral light emission,non-Hermitian symmetry breaking,vortex light beams,spin-orbit interaction,microlaser,telecommunication wavelength
更新于2025-09-23 15:21:01
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Widely tunable ytterbium-doped single-frequency all-fiber laser
摘要： We demonstrate a widely tunable ytterbium-doped single frequency all-fiber laser with a computer-controlled tunable filter and a home-made comb spectrum filter. The comb filter is realized by fusing a single strand of polarization maintaining optical fiber into a double-circulator interferometer. The spectral performance of the comb filter is verified by theoretical and experimental studies. Wavelength-tunable single frequency operation in about 55 nm (1030–1085 nm) range can be achieved through the combined effect of these two filters. The experimental outcomes exhibit that an ultra-narrow linewidth of 435 Hz with high optical signal to noise ratio greater than 50 dB and high stability of operation wavelength and output power (0.016 nm and 0.38 dB, respectively) at room temperature. Our studies provide a new way to obtain the wide-range tunable single frequency fiber laser.
关键词： Wavelength-tunable,Fiber laser,Ultra-narrow linewidth,Single frequency,Comb spectrum filter
更新于2025-09-23 15:21:01
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Tunable C-band and L-band multi-wavelength erbium-doped fiber ring laser based on a triple-core photonic crystal fiber with polarization-dependent loss
摘要： A tunable C-band and L-band multi-wavelength erbium-doped fiber laser (MW-EDFL) based on a novel fiber filter is proposed and experimentally demonstrated. The fiber filter is composed of a segment of triple-core photonic crystal fiber (TCPCF) and a segment of multi-mode fiber (MMF) between single mode fibers, which is inserted into the ring cavity of MW-EDFL as tuning component and wavelength selector. Based on the axial strain response of fiber filter, a tunable single-, dual- and triple-wavelength laser can be obtained with the tunable range of 19.58 nm, 10.34 nm, 6.84 nm, respectively. Meanwhile, the side-mode suppression ratio of lasing output is higher than 50 dB and the 3 dB linewidth is 0.026 nm for single wavelength lasing. Moreover, the lasing outputs are proved to be very stable at room temperature with the maximum wavelength shift of 0.06 nm and power fluctuation of 0.96 dB. Such a MW-EDFL with relatively simple structure and easy preparation has wide applications in important fields such as medicine, military, communication, and sensing.
关键词： In-line MZI,Tunable and switchable,Multi-wavelength erbium-doped fiber laser
更新于2025-09-23 15:21:01
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UV-shielding and wavelength conversion by centric diatom nanopatterned frustules
摘要： Diatoms can represent the major component of phytoplankton and contribute massively to global primary production in the oceans. Over tens of millions of years they developed an intricate porous silica shell, the frustule, which ensures mechanical protection, sorting of nutrients from harmful agents, and optimization of light harvesting. Several groups of microalgae evolved different strategies of protection towards ultraviolet radiation (UVR), which is harmful for all living organisms mainly through the formation of dimeric photoproducts between adjacent pyrimidines in DNA. Even in presence of low concentrations of UV-absorbing compounds, several diatoms exhibit significant UVR tolerance. We here investigated the mechanisms involved in UVR screening by diatom silica investments focusing on single frustules of a planktonic centric diatom, Coscinodiscus wailesii, analyzing absorption by the silica matrix, diffraction by frustule ultrastructure and also UV conversion into photosynthetically active radiation exerted by nanostructured silica photoluminescence. We identified the defects and organic residuals incorporated in frustule silica matrix which mainly contribute to absorption; simulated and measured the spatial distribution of UVR transmitted by a single valve, finding that it is confined far away from the diatom valve itself; furthermore, we showed how UV-to-blue radiation conversion (which is particularly significant for photosynthetic productivity) is more efficient than other emission transitions in the visible spectral range.
关键词： frustules,wavelength conversion,photoluminescence,UV-shielding,diatoms
更新于2025-09-23 15:21:01
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FIBRE BRAGG GRATING SENSOR SYSTEM FOR TEMPERATURE APPLICATION
摘要： A practical pass-through type fibre Bragg grating (FBG) temperature sensor system have been designed and experimentally investigated. The performance of FBG was evaluated with the varying of focusing elements in harsh environments, under direct sunlight. The sensor head of FBG was designed to be focused with convex and hand lens. Results shows that the Bragg wavelength shift, ????? increase proportionally with the temperature for both systems. The sensitivities of FBG were recorded to be 0.0107 and 0.0122 nm °C-1 for the system where convex and hand lens applied to the FBG’s sensor head respectively.
关键词： focusing element,temperature sensor,Fibre Bragg grating,Bragg wavelength shift
更新于2025-09-23 15:21:01
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Quality of Transmission Aware Optical Networking using Enhanced Gaussian Noise Model
摘要： We present a new joint routing, wavelength, and power allocation method for optical network planning. The introduced gradient-based convex optimization approach has a lower computational complexity, compared to common linear programming techniques, suitable for both static as well as time-critical dynamic network planning with fast convergence requirement. The proposed scheme takes physical-layer impairments into account, using the enhanced Gaussian noise nonlinear model. In contrast to methods exploiting the theoretical full link spectrum utilization assumption (fully occupied fiber-optic C-band spectrum), we focus on maximizing the network achievable rate (AR) and minimum signal-to-noise ratio (SNR) margin of networks with partial spectrum utilization in their links, relevant to the majority of empirical metro network scenarios. According to numerical results, the network achievable rate can be improved around 17% by performing power optimization over the individual launch power of network lightpaths compared to optimizing a single flat (equal) launch power for all the lightpaths. Moreover, the minimum SNR margin of the simulated network is improved by about 2.3 dB. Finally, it is observed that maximizing the network minimum SNR margin needs the launch power of each lightpath to be proportional to the total nonlinear interference noise efficiency influencing the lightpath.
关键词： non-linear effects,routing and wavelength assignment,optical network optimization,network planning,Enhanced Gaussian noise model,power allocation,coherent transmission
更新于2025-09-23 15:21:01