The authors demonstrate a composite microring laser formed by immersing a silica microfiber knot in a rhodamine 6G dye solution. When the dye molecules are evanescently pumped by 532nm wavelength laser pulses guided along a 350μm diameter knot, lasing oscillation occurs inside the evanescently coupled closed-ring microcavity with a linewidth of about 0.06nm. Laser emission around 570 and 580nm wavelengths, which is evanescently coupled back into the microfiber, is observed with a threshold of about 9.2μJ∕pulse. The use of the microfiber knot cavity suggests a convenient and efficient approach to both pumping and collection of the evanescent-wave-coupled dye laser.

We demonstrate a compact hybrid structure red-green-ultraviolet three-color laser consisting of three distinct semiconductor nanowires (CdSe, CdS and ZnO) attached to a silica microfiber, which is pumped by 355 nm wavelength laser pulses. The exciting of the nanowires and the collection of the photoluminescence (PL) are implemented by means of evanescent coupling through the same silica microfiber. When pump energy higher than 1.3 microJ, three spatially and spectrally distinct lasing groups can be measured at the same output port simultaneously. The approach can be extended to other materials to produce hybrid lasers that cover ultraviolet to near infrared spectral regions.

Bending losses of nanofibers or nanowires with circular 90 degrees bends are simulated using a three-dimensional finite-difference time-domain (3D-FDTD) method. Dependences of bending losses on wavelength and polarization of guided light are investigated, as well as the diameters, refractive indices, and bending radii of nanowires. The acceptable bending losses (approximately 1 dB/90 degrees) predicted in glass, polymer, and semiconductor nanowires with bending radii down to micrometer level may offer valuable references for assembling highly compact photonic integrated circuits or devices with optical nanowires.

We demonstrate that a tensor product structure and optical analogy of quantum entanglement can be obtained by introducing pseudorandom phase sequences into classical fields with two orthogonal modes. Using the classical analogy, we discuss efficient simulation of several typical quantum states, including product state, Bell states, GHZ state, and W state. By performing quadrature demodulation scheme, we propose a sequence permutation mechanism to simulate certain quantum states and a generalized gate array model to simulate quantum algorithm, such as Shor's algorithm and Grover's algorithm. The research on classical simulation of quantum states is important, for it not only enables potential beyond quantum computation, but also provides useful insights into fundamental concepts of quantum mechanics. * Electronic address: jianfu@zju.edu.cn 1 arXiv:1505.00555v4 [quant-ph]

Since the Open Geospatial Consortium (OGC) proposed the geospatial Web Processing Service (WPS), standard OGC Web Service (OWS)-based geospatial processing has become the major type of distributed geospatial application. However, improving the performance and sustainability of the distributed geospatial applications has become the dominant challenge for OWSs. This paper presents the construction of an elastic parallel OGC WPS service on a cloud-based cluster and the designs of a high-performance, cloud-based WPS service architecture, the scalability scheme of the cloud, and the algorithm of the elastic parallel geoprocessing. Experiments of the remote sensing data processing service demonstrate that our proposed method can provide a higher-performance WPS service OPEN ACCESSSustainability 2015, 7 14246 that uses less computing resources. Our proposed method can also help institutions reduce hardware costs, raise the rate of hardware usage, and conserve energy, which is important in building green and sustainable geospatial services or applications.