RESUMEN
A high resolution imaging of the temperature and microwave near field can be a powerful tool for the non-destructive testing of materials and devices. However, it is presently a very challenging issue due to the lack of a practical measurement pathway. In this work, we propose and demonstrate experimentally a practical method resolving the issue by using a conventional CCD-based optical indicator microscope system. The present method utilizes the heat caused by an interaction between the material and an electromagnetic wave, and visualizes the heat source distribution from the measured photoelastic images. By using a slide glass coated by a metal thin film as the indicator, we obtain optically resolved temperature, electric, and magnetic microwave near field images selectively with a comparable sensitivity, response time, and bandwidth of existing methods. The present method provides a practical way to characterize the thermal and electromagnetic properties of materials and devices under various environments.
RESUMEN
The propagation of the light trough dielectric-metal-dielectric conical waveguide is described by the coupling modes between internal and external waveguides. The energy pumping from internal to the external waveguide has a resonant behavior and is very sensitive to the variations of the system parameters. The simplified model of this process realization is the light flash at the end of the conical metal covered tip of the optical fiber that crosses the liquid-air interface. Here, as an external waveguide serves the liquid meniscus formed at the tip of the optical fiber. In this condition, the shift of liquid surface by 50 nm toward the tip end brings significant changes in the transferred radiation power. Ability to register nanometric displacements (nanovibrations) of the liquid surface opens up new ways to create sensitive sensors for different purposes.