A nonlinear hybrid plasmonic slot waveguide composed of periodically poled lithium niobate (PPLN) and two separated silver films is investigated. The effective refractive index, propagation length, and energy confinement of the hybrid anti-symmetric mode in this waveguide are calculated using the structure parameters at the fundamental wavelength of λ = 1550 nm and its second harmonic (SH) λ = 775 nm. Through the above indices, coupling efficiency (maximum SH conversion efficiency during propagation) and peak position (propagation location of the conversion efficiency) of SH generation are analyzed. Finally, higher conversion efficiency can be achieved at a shorter propagation distance by changing the waveguide into a tapered structure.

No abstract

No abstract

A suspended fire fighting robot was presented, and the prototype was developed. The robot changed its posture by the blowing forces from the fans; the PID algorithm was analyzed and applied to control the rotating speeds of the fans in order to realize posture adjustment. A high speed propeller driven by an engine pushed the robot approach to the target; the relation between steering angle and thrust force was studied; a sliding table structure was developed to make the robot move steadily by changing the gravity position; the control algorithm of the propulsion system was analyzed.

In this paper, the kinetic Monte Carlo simulations of the self-assembly quantum rings (QRs) based on the substrate engineering, which is related to the eventual shape of the formed quantum ring, are implemented. According to the simulation results, the availability of the QR with tunable size and the formation of smooth shape on the ideal flat substrate are checked. Through designing the substrate engineering, i.e., changing the depth, the separation and the ratio between the radius and the height of the embedded inclusions, the position and size of QR can be controlled and eventually the growth strategy of optimizing the self-assembly QRs is accomplished.