Mechanism for graphene-based optoelectronic switches by tuning surface plasmon-polaritons in monolayer graphene

It is shown that one can explore the optical conductivity of graphene, together with the ability of controlling its electronic density by an applied gate voltage, in order to achieve resonant coupling between an external electromagnetic radiation and surface plasmon-polaritons in the graphene layer. This opens the possibility of electrical control of the intensity of light reflected inside a prism placed on top of the graphene layer, by switching between the regimes of total reflection and total absorption. The predicted effect can be used to build graphene-based opto-electronic switches.Comment: 5 page

Test equipment and its effect on the calibration of instrument transformers

State-approved test centres in Germany supplying accuracy tests for instrument transformers must, in the future, provide measurement uncertainty budgets for their quality management systems. In this work, the cause of ratio error and phase displacement of instrument transformers are therefore discussed. The traceability to the national standards of PTB, the attainable uncertainty, and the permitted error limits of test equipment for testing instrument transformers are presented. Finally, an example of an uncertainty budget for a current transformer of the class 0,2 S is given