1,721,178 research outputs found
Design of germanium-silicon carbide hybrid waveguides for mid-infrared third-order parametric conversion
No full textWe propose a mid-infrared (MIR) waveguide in which two pure photonic fundamental modes are perfect phase-matched for third harmonic generation (THG) and triple photon generation (TPG). The waveguide is based on the germanium–silicon carbide–germanium (Ge–SiC–Ge) hybrid structure. Leveraging the anomalous dispersion of SiC near the resonance, the THG phase mismatch between two fundamental modes can be overcome. By carefully engineering the nonlinear mode overlap, the MIR THG performance is investigated in detail. In addition, a MIR TPG rate of ~10-3Hz is estimated. The proposed scheme provides an integrated platform for future MIR all-optical signal processing and quantum signal processing
Dataset for All-Optical Implementation of the Ant Colony Optimization Algorithm
No full textDataset supports:
Hu, W. et al (2016). All-optical implementation of the ant colony optimization algorithm. Scientific Reports, 1-15. </span
Fundamental and third harmonic mode coupling induced single soliton generation in Kerr microresonators
No full textThe single soliton propagating in a microresonator (MRR) is characterized by a smooth spectrum. However, the number of solitons that propagate in an MRR in the anomalous dispersion regime is usually stochastic and gives rise to a complex spectrum. In this paper, we introduce a new passive mechanism based on third-harmonic-induced nonlinear coupling for the formation of a single deterministic soliton in an MRR. We show that with appropriate fundamental and third harmonic mode coupling strength and a slight phase mismatch, deterministic single soliton generation can be realized by simply scanning the detuning of a continuous wave serving as a pump. Under strong mode coupling strength, a relatively smaller wave vector mismatch within suitable range can be used for single soliton generation. Our work provides a potential approach for on-chip generation of coherent optical Kerr combs and efficient THG conversion
All-optical implementation of the ant colony optimization algorithm
No full textWe report all-optical implementation of the optimization algorithm for the famous “ant colony” problem. Ant colonies progressively optimize pathway to food discovered by one of the ants through identifying the discovered route with volatile chemicals (pheromones) secreted on the way back from the food deposit. Mathematically this is an important example of graph optimization problem with dynamically changing parameters. Using an optical network with nonlinear waveguides to represent the graph and a feedback loop, we experimentally show that photons traveling through the network behave like ants that dynamically modify the environment to find the shortest pathway to any chosen point in the graph. This proof-of-principle demonstration illustrates how transient nonlinearity in the optical system can be exploited to tackle complex optimization problems directly, on the hardware level, which may be used for self-routing of optical signals in transparent communication networks and energy flow in photonic systems
Crossing-free on-chip 2×2 polarization-diverse switch
No full textWe propose and demonstrate an on-chip 2× 2 polarization-diverse switch for simultaneously handling two-group polarization multiplexed signals with waveguide crossing-free design. Each input polarization tributary can be independently switched and less than 1 dB power penalties are experimentally observed.</p
Computing matrix inversion with optical networks
Full text linkWith this paper we bring about a discussion on the computing potential of complex optical networks and provide experimental demonstration that an optical fiber network can be used as an analog processor to calculate matrix inversion. A 3x3 matrix is inverted as a proof-of-concept demonstration using a fiber network containing three nodes and operating at telecomm wavelength. For an NxN matrix, the overall solving time (including setting time of the matrix elements and calculation time of inversion) scales as O(N2), whereas matrix inversion by most advanced computer algorithms requires ~O(N2.37) computational time. For well-conditioned matrices, the error of the inversion performed optically is found to be around 3%, limited by the accuracy of measurement equipment
Computing with complex optical networks
No full textUsing simple fiber networks for proof-of-principle demonstrations, we give examples of natural computing in linear optical networks, like solving polynomial (P) and nondeterministic polynomial (NP) problems, and in nonlinear optical networks, like metaheuristic optimization and neuromorphic computing
Third harmonic and triple photon generation in photonic crystal fiber with subwavelength-scale air holes
No full textWe theoretically study third harmonic and triple photon generation (THG/TPG) in photonic crystal fiber (PCF). 9% THG conversion efficiency and 28 triplets/s generation rate are achievable in the proposed PCF
Pulse Shape Tuning for 1064 nm Nanosecond MOPA Fibre Laser
No full textAbstractFor a high power 1064 nm nanosecond MOPA pulse fibre laser, the seeding pulse shape is distorted after amplified by pre-amplifier and power-amplifier stages under the effect of gain saturation. As the pulse shape is crucial for some industrial applications, the distortion of eight different shapes of seeding pulses is experimentally studied, and the Stimulated Raman Scattering (SRS) for several shapes is also investigated
Theoretical study of bicharacteristic waveguide for fundamental-mode phase-matched SHG from MIR to NIR
No full textIn this paper, a bicharacteristic waveguide (BW) is proposed for fundamental-mode phase-matched second harmonic generation (SHG) from mid-infrared (MIR) to near-infrared (NIR). The required phase matching condition (PMC) is satisfied between the fundamental plasmonic mode at 3100 nm and the photonic mode at 1550 nm. With 1 W pump power, the SHG conversion efficiency of 4.173% can be obtained in 90.3 μm length waveguide. Moreover, the SHG conversion can be enhanced by using a microring resonator (MRR). By optimizing the MRR, the SHG conversion efficiency is increased to 8.30%. The proposed waveguide can also provide a promising platform for upconversion detection. By using an on-chip cascaded configuration, a gas sensor with the capability of MIR absorption and NIR detection is proposed. It is found that the detection limit (DL) can reach 1.04 nmol/L with 100 mW pump power, which shows significant enhancement compared with direct MIR absorption and detection.</p
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