Brillouin scattering based fiber optic strain sensor
In this study, stress-induced Brillouin scattering was experimentally analyzed by the weight applied to a specific point of the classical single mode fiber cable. A Brillouin optical time domain analysis (BOTDA) test system was developed for frequency shifts according to different weights applied. For different weights, the frequency values of the scattered light are obtained from the specific point of the fiber cable.
The analyzes of the Brillouin scattering for the different fiber types
In this study, Brillouin scattering is experimentally analyzed in the single mode fiber and dispersion shifted fiber optic cable. For this reason, wavelength of the 1550 nm laser is varied between 1526 nm and 1570 nm, and Brillouin shift is measured for both fiber types. Consequently, Brillouin scattering is higher in the single mode fiber.
Microwave source with enhanced radiation power based on orbitron MASERs
We have proposed the design of high power microwave source in a vacuum tube based on the theory of negative mass instability. The proposed source does not operate based on a slow-wave structure but instead makes use of accelerated charged particles. In our structure, an electron emitter injects the charged particles into to the cavity. Emitted particles move around the anode, which leads to electron acceleration and emission of electromagnetic waves with a specific frequency. In this paper, we have enhanced the output power and frequency of microwave source by variation of particles initial energy and the number of anodes incorporating their specific arrangement and applied voltages. Working at room temperature, compactness, wide bandwidth, and tunability of output frequency are among the advantages of the proposed source.