Design of a reflection-suppressed all-optical diode based on asymmetric L-shaped nonlinear photonic crystal cavity

A simple design method for suppressing the reflection of the all-optical diode based on the L-shaped photonic crystal (PC) cavity is proposed. Analyzing the linear resonant characteristics of the PC cavity and using the nonlinear coupled-mode theory, the strategy for obtaining reflection-suppressed structure is illustrated. Based on the design rule, a “reflection-suppressed all-optical diode” is presented, and numerical solutions indicate that the designed structure has a small reflection as well as an extremely large nonreciprocal transmission ratio

Interfacial Void Model for Corrosion Pit Initiation on Aluminum

A model for pit initiation during galvanostatic anodic etching of aluminum in acid chloride-containing solutions was developed. The predictions were compared to experimental potential transients and pit-size distributions. The model presumed that pits initiated from subsurface nanoscale voids, which were exposed by uniform corrosion. Void concentrations fit from potential transients depended on times of caustic and acid exposure before etching, in agreement with prior characterization of the voids by positron annihilation measurements. The model yielded realistic predictions of the effect of applied current density and temperature on the potential transients. The effective void concentration was found to increase with the chloride concentration in the etching solution; this suggested that higher chloride concentrations inhibit passivation of newly exposed voids, enhancing their survival probability. On the whole, the interfacial void model provided a promising quantitative description of pit initiation during anodic etching

A Basic Study on Path Teaching Method for a Mobile Robot Using a Digital Camera

This paper proposes a novel path teaching method for a mobile robot. In this method an operator takes pictures at significant points such as turning points, half way points and a destination on robot´s path by a digital camera. Then, the operator teaches the robot landmarks to recognize the images and actions for the robot to take at the significant points. The robot travels autonomously searching the landmarks and obeys the instructions when it recognizes reaching the significant points. By using this method, it is possible to teach paths for the mobile robot more easily. In this paper, outline of the proposed method and results of fundamental experiments in both indoor and outdoor environment to confirm possibility of the method are described