- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Optical frequency comb generation with low temperature reactive sputtered silicon nitride waveguides
摘要： Integrated silicon nitride (SiN) waveguides with anomalous dispersion have the potential to bring practical nonlinear optics to mainstream photonic integrated circuits. However, high-stress and high-processing temperatures remain an obstacle to mass adoption. We report low-stress, high-confinement, dispersion-engineered SiN waveguides utilizing low temperature grown reactive sputtered thin-films. We demonstrate a microring resonator with an intrinsic quality factor of 6.6 × 105, which enabled us to generate a native free spectral range spaced frequency comb with an estimated on-chip pump power of 850 mW. Importantly, the peak processing temperature is 400 ○C making this approach fully back-end compatible for hybrid integration with preprocessed CMOS substrates and temperature sensitive photonic platforms such as lithium niobate on insulator.
关键词： reactive sputtering,optical frequency comb,silicon nitride waveguides,photonic integrated circuits,nonlinear optics
更新于2025-09-19 17:13:59
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Characteristics enhancement of one-section and two-stepwise microchannels for cooling high-concentration multi-junction photovoltaic cells
摘要： This paper presents the development of simple, effective, and economic microchannel systems for cooling high-concentration multi-junction photovoltaic (HCMJPV) cells. The developed cooling system uses a short cooling fluid path concept with either one or two microchannel sections per the fluid path. The work is conducted using a 3D numerical model that is based on the finite volume method. The effects of design parameters on the thermal characteristics of one and two-section microchannels and output power of the HCMJPV cells are comprehensively investigated. Cooling systems that attained the largest net output power of HCMJPV cells are identified. Developed cooling systems achieved superior characteristics compared to the existing state of the art system. The two-stepwise microchannel cooling system achieves the best temperature uniformity, whereas the constant-width one-section microchannel cooling system achieves slightly better characteristics than the two-stepwise system. The proposed constant-width one-section cooling system achieves comparable standard deviation and lower surface temperature (35.65 °C), pressure drop (68.41%) and microchannel thermal resistance (49.57%) along with higher generated power (8.27%), net output power (8.44%) and overall heat transfer coefficient (175.8%) than the existed cooling system in literature. The developed cooling system allows the cells to produce an extra 820.5MWh/m2 of cells during their lifetime.
关键词： Hybrid jet impingement-microchannel cooling,Pumping power,High-concentration multi-junction photovoltaic,Stepwise microchannel cooling,High power integrated circuits,Net output power
更新于2025-09-19 17:13:59
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Numerical Simulation of an InP Photonic Integrated Cross-Connect for Deep Neural Networks on Chip
摘要： We propose a novel photonic accelerator architecture based on a broadcast-and-weight approach for a deep neural network through a photonic integrated cross-connect. The single neuron and the complete neural network operation are numerically simulated. The weight calibration and weighted addition are reproduced and demonstrated to behave as in the experimental measurements. A dynamic range higher than 25 dB is predicted, in line with the measurements. The weighted addition operation is also simulated and analyzed as a function of the optical crosstalk and the number of input colors involved. In particular, while an increase in optical crosstalk negatively influences the simulated error, a greater number of channels results in better performance. The iris flower classification problem is solved by implementing the weight matrix of a trained three-layer deep neural network. The performance of the corresponding photonic implementation is numerically investigated by tuning the optical crosstalk and waveguide loss, in order to anticipate energy consumption per operation. The analysis of the prediction error as a function of the optical crosstalk per layer suggests that the first layer is essential to the final accuracy. The ultimate accuracy shows a quasi-linear dependence between the prediction accuracy and the errors per layer for a normalized root mean square error lower than 0.09, suggesting that there is a maximum level of error permitted at the first layer for guaranteeing a final accuracy higher than 89%. However, it is still possible to find good local minima even for an error higher than 0.09, due to the stochastic nature of the network we are analyzing. Lower levels of path losses allow for half the power consumption at the matrix multiplication unit, for the same error level, offering opportunities for further improved performance. The good agreement between the simulations and the experiments offers a solid base for studying the scalability of this kind of network.
关键词： deep neural network,photonic neural network,image classification,semiconductor optical amplifiers,artificial neural networks,photonic integrated circuits
更新于2025-09-19 17:13:59
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Complete Scene Reconstruction by Merging Images and Laser Scans
摘要： Optical fibre transmission has enabled greatly increased transmission rates with 10 Gb/s common in local area networks. End users find wireless access highly convenient for mobile communication. However, limited spectrum availability at microwave frequencies results in per-user transmission rates limited to much lower values, e.g., 500 Mb/s for 5-GHz band IEEE 802.11ac. Extending the high data-rate capacity of optical fiber transmission to wireless devices requires greatly increased carrier frequencies. This paper will describe how photonic techniques can enable ultrahigh capacity wireless data distribution and transmission using signals at millimeter-wave and TeraHertz (THz) frequencies.
关键词： photonic integrated circuits,microwave photonics,Broadband communication,optical mixing,optical heterodyne,millimeter (mm)-wave generation,optical phase lock loops,semiconductor lasers
更新于2025-09-19 17:13:59
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High-Power, Narrow-Linewidth, Miniaturized Silicon Photonic Tunable Laser with Accurate Frequency Control
摘要： We have demonstrated a hybrid-integrated silicon photonic (SiPh) tunable laser in a miniaturized package, suitable for coherent modules in small form factors such as OSFP and QSFP-DD. Through the integration of an in-house-designed high-power semiconductor optical amplifier (SOA), the developed SiPh laser has achieved a record-high output power of 21.5 dBm across the C-band. Also, this laser exhibits narrow linewidths down to 60 kHz, SMSR larger than 50 dB, low relative intensity noise below -150 dB/Hz, and a broad tuning range of 65 nm. These performance parameters are preferable for 400 Gb/s and beyond coherent communications using advanced high-order modulation formats. Moreover, an on-chip integrated sensor technology was developed for accurate laser frequency control. We have achieved 1 GHz frequency stability of SiPh laser against SOA current changes or package temperature variations between 10 oC and 80 oC. We further show the feasibility of this developed SiPh laser for 64 Gbaud, 16/64 QAM coherent transmission by integrating with an in-house InP-PLC hybrid coherent optical subassembly (COSA).
关键词： Wavelength tunable lasers,Silicon photonics,Hybrid integration,Photonic integrated circuits,Semiconductor optical amplifiers
更新于2025-09-19 17:13:59
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All-optical InAsP/InP nanowire switches integrated in a Si photonic crystal
摘要： We report the successful demonstration of all-optical switching using a sub-wavelength InP/InAsP nanowire integrated in a silicon photonic crystal at telecommunication wavelengths. In this work, we employed two different hybrid nanowire cavities based on an air-trench in photonic crystals. These hybrid cavities have the advantages of both material functionality of III-V material and the low propagation loss of the silicon waveguide. The nanowire induced line-defect photonic crystal cavity shows a Q-factor of 25000, higher than the hybrid systems we previously demonstrated. The switching time is 150 ps, which is among the fastest nanowire switches reported. We found that the switching time was clearly dependent on the Q-factor. From measurements performed while changing pump power, we have estimated the switching energy to be a few hundred femtojoules. This value is lower than that of a reference silicon photonic crystal cavity without a nanowire and an air trench under the same pumping condition. This indicates that the InP/InAsP nanowire integrated in a silicon photonic crystal has potential to contribute to reducing the switching energy.
关键词： all-optical switch,AFM manipulation,nanophotonics,photonic crystal,nanowire,photonic integrated circuits
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Epitaxial Lifted-Off Thin Film GaInP/GaAs/GaInNAsSb Lattice-Matched Triple Junction Solar Cells
摘要： The increasing number of computational servers in data centers is imposing tighter constraints on the networking infrastructure. Scalable power efficient optical interconnect network becomes necessary to leverage the bandwidth capacity of current electronic switches or opto-electronic components. Hence, novel optical interconnect technology can enhance the network capacity by harnessing the feasibility of simultaneous processing of optical signal in the wavelength and time domains. In this paper, we present a four channel optical passive wavelength-striped mapping (PWSM) device, which passively time compresses/expands serial packets through optical wavelength multiplexing/demultiplexing. The PWSM device, which has a 1 × 4 channel optical wavelength demultiplexer with integrated optical delay lines, is designed in a low-loss Si3N4 (propagation loss ～3.1 dB/m) waveguide platform. The PWSM device multiplexes/demultiplexes four WDM channels and offsets in time the adjacent channels to optically serialize/de-serialize data packets. In this demonstration, a 64 ns long data packet is formed at the output of the device by combining four 16 ns data segments of the packet in time domain. Incremental optical insertion loss between adjacent channels is ～9.7 dB due to the integrated passive optical delay waveguides. The data rate of the four segmented packets and the combined packet is 25 Gb/sec. We have measured a bit error rate performance below 1 ×10?9 for the 64 ns serial data packet regenerated by the PWSM device for a received optical power of –6.7 dBm.
关键词： silica and silicon nitride photonics,wavelength filtering devices,Photonic integrated circuits
更新于2025-09-19 17:13:59
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Membrane III-V/Si DFB Laser using Uniform Grating and Width-Modulated Si Waveguide
摘要： Membrane buried-heterostructure III-V/Si distributed feedback (DFB) lasers with a stopband-modulated cavity on a Si substrate have been developed. The membrane III-V layers with 230-nm thick enable us to construct an optical supermode with a 220-nm-thick Si waveguide that is used in standard Si photonics platform. We employ a uniform grating and Si waveguide, in which Si waveguide width is modulated to control the center wavelength of the stopband. The cavity can be designed by controlling the modulation width and modulation length of Si waveguide. Therefore, it is easy to engineer and fabricate the laser cavity compared with the cavity using λ/4-phase shift grating. Output light from the cavity is coupled to Si waveguide through InP inverse taper waveguide, and then coupled to SiOx waveguide through Si inverse taper waveguide, which provides the 2-dB fiber coupling loss. We have demonstrated single-mode lasing by using Si waveguide, where its width is increased 80 nm at the center of the cavity. The threshold current and maximum fiber output power are 3 mA and 4 mW, respectively. By extending the active region length to 1 mm, 17-mW fiber coupled output power is obtained. High-temperature operation up to 130°C is also obtained with a 1-mW fiber output power.
关键词： photonic integrated circuits,semiconductor lasers,Silicon photonics
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 14th Malaysia International Conference on Communication (MICC) - Selangor, Malaysia (2019.12.2-2019.12.4)] 2019 IEEE 14th Malaysia International Conference on Communication (MICC) - Analyzing the Effects of LED Lamp Arrangements on Performance of an Indoor Visible Light Communication System
摘要： We report the results of a study of an optical sensor based on a channel-drop technique with two cascaded cavities in photonic-crystal slabs. Quality factors and intensities of the resonant modes of the sensor were analyzed with three-dimensional simulations. With the introduction of a re?ector in the bus-channel and by control of the coupling between the two cavities and the drop-channel, the drop ef?ciency can be remarkably increased. In addition to the simulation, the two cavity sensor is fabricated and tested for optical response to water and oil in?ltration. Both direct visual imaging and quantitative analysis were applied in experiment. A difference of refractive index Δn = 0.12 between water and oil samples results in a wavelength shift of 18.3 nm, which greatly matches the simulation result of 20 nm and indicates a sensitivity of 153 nm RIU?1. Both resonant peaks for water and oil in?ltration have good selectivity in their transmission spectrum. The contrast between the broadband output of the bus-channel and the highly wavelength-selective outputs of the drop-channel opens opportunities for the two cascaded-cavity system as a fundamental building block for a multiplex drop-channel array for all-optical sensing, which can be widely used for bio/chemical detection and environmental monitoring.
关键词： optical waveguide,optical coupling,optical sensors,multiplexing,optical devices,photonic integrated circuits,photonic crystals,Cavity resonators
更新于2025-09-19 17:13:59
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High-Gain Metasurface in Polyimide On-Chip Antenna Based on CRLH-TL for Sub-Terahertz Integrated Circuits
摘要： this paper presents a novel on-chip antenna using standard cMoS-technology based on metasurface implemented on two-layers polyimide substrates with a thickness of 500 μm. the aluminium ground-plane with thickness of 3 μm is sandwiched between the two-layers. concentric dielectric-rings are etched in the ground-plane under the radiation patches implemented on the top-layer. the radiation patches comprise concentric metal-rings that are arranged in a 3 × 3 matrix. The antennas are excited by coupling electromagnetic energy through the gaps of the concentric dielectric-rings in the ground-plane using a microstrip feedline created on the bottom polyimide-layer. the open-ended feedline is split in three-branches that are aligned under the radiation elements to couple the maximum energy. in this structure, the concentric metal-rings essentially act as series left-handed capacitances CL that extend the effective aperture area of the antenna without affecting its dimensions, and the concentric dielectric rings etched in the ground-plane act as shunt left-handed inductors LL, which suppress the surface-waves and reduce the substrates losses that leads to improved bandwidth and radiation properties. The overall structure behaves like a metasurface that is shown to exhibit a very large bandwidth of 0.350–0.385 THz with an average radiation gain and efficiency of 8.15dBi and 65.71%, respectively. It has dimensions of 6 × 6 × 1 mm3 that makes it suitable for on-chip implementation.
关键词： metasurface,integrated circuits,on-chip antenna,polyimide substrate,sub-terahertz
更新于2025-09-19 17:13:59