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Large-scale quantum networks rely on quantum repeaters that distribute entanglement efficiently in a multi-mode and heralded fashion over multiple network nodes. Next to optical quantum memories, most quantum repeater architectures also require multiplexed sources of entangled photon pairs, as well as photon detection that can distinguish between the multiplexed modes. We demonstrate the generation and characterization of frequency multiplexed photon pairs by employing cavity-enhanced spontaneous parametric down-conversion in a nonlinear crystal and a virtually-imaged phase array that allows mapping of spectral modes onto distinct spatial modes. Through coincidence measurements, we demonstrate non-classical correlations between energy-correlated photon pairs and a strong reduction of correlations between the non-correlated photons. Our investigation demonstrates that both our photon-pair source and the detection setup are suitable for creating a frequency multiplexed quantum repeater., Comment: 16 pages, 14 figures (including supplementary information)

The vehicle scheduling in the logistics system of the iron and steel plant is a key issue to the resource allocation and inventory running efficiency of downstream production line. The traditional vehicle scheduling strategy does not analyze the logistics cost and efficiency of inventory scheduling from the aspects of vehicle storage order and time, resulting in low scheduling efficiency and high cost. Taking the right order and time of arrival of the vehicle into the plant and considering the multi-vehicle scheduling can effectively improve the efficiency of inventory and decrease the cost. So, the paper established an integral programming model that can minimize the factory time and the minimum operating cost of the conveyor belt. Then an improved Glowworm Swarm Optimization algorithm was proposed to solve the complex model, and the adaptive strategy was improved to enhance the individual search ability, and the Levy variation was introduced in the process of the Firefly moving. At last, the improved algorithm was validated by the simulation results.

A scheduling model with the least total time was proposed to deal with the collision avoidance of multi-crane scheduling with the transitive priority changing rules in the steel product warehouse. The cuckoo search algorithm (CS) was applied to optimize multi-crane scheduling. In order to get a better performance, an improved CS (ICS) was provided by adding adaptive dynamic steps, dynamically changing the discovery probability and the local optimal solution mutation mechanism. The ICS has the characteristics of fast convergence, high solution precision and strong ability to jump out of the local optimum. The provided algorithm was validated by the simulation example.

The sensor’s waking strategy is critical to the sensor network. The basic mathematical model of waking strategy is TSP problem. Some typical intelligent algorithms for TSP problem model include ant colony algorithm, genetic algorithm and so on. On the basis of the maximum and minimum ant colony algorithm, this paper improves the following disadvantages: According to the principle of choosing the city based on the pheromone principle, the non-contract principle is added, The principle of city selection and make it in the process of selecting the city, the priority to follow the principle of non-contract; in a single path after the help of the enumeration algorithm with the special advantages, refer to the enumeration algorithm part of the results of the re-processing of the path, The path can cover the search space. The improved algorithm avoids the occurrence of stagnation to a certain extent, weakening the blindness of search. The possibility of the results is increased by 25%, single results of the calculation time is reduced by 89.79%.

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Two 915 nm diode laser short bars were used as sub-module to manufacture high brightness fiber coupled module with continuous wave(CW) output power.Firstly,beam shaping technology was employed for each sub-module to enhance its beam quality.Secondly,the two beams were stacked in direction of lower beam parameter product by means of spatial multiplexing technology.Finally,the laser was focusing into a multimode fiber with 200 μm core diameter and NA=0.22 by optimized lens by focusing lens.Experiment results show that the beam waist diameter at focal plane is 105.4 μm when driving current is 52.5 A,the optical power output from fiber can reach to 72.6 W with a brightness of 6.08 MW/(cm2·sr),and the wallplug efficiency is 42.2% when driving current is 52.5 A.The character of heat dissipation was studied by means of measuring spectrum with different current,and the results prove that the module has favorable heat dissipation.