Mohammad Kouhi

In this work, a magnetized cold plasma photonic crystal (MCP–PC) gas sensor is investigated. The transfer matrix method (TMM) is employed to calculate transmittance spectra of the proposed MCP–PC gas sensor. Sensitivity, quality factor, and figure of merit were examined as performance parameters of the sensor. These performance parameters are affected by incident angle, electron density, magnetic field strength, and cavity thickness. The results demonstrate that the sensitivity of the proposed sensor is highest for strong magnetic fields and high electron densities. However, achieving a higher quality factor (900) and figure of merit (4000 1/RIU) along with high sensitivity (37.5 GHz/RIU) is possible by choosing a moderate magnetic field (0.55 T). The findings of this study demonstrate that the proposed MCP-PC gas sensor is a powerful tunable sensor via magnetic field and provides a novel concept for advanced photonic-plasma devices.

In this paper, two structures of surface plasmon resonance fiber optic biosensors with the addition of a thin layer of titanium dioxide and barium titanate are introduced and studied comparatively. The sensitivity of these biosensors has been calculated using the transfer matrix method. Adding a thin layer of barium titanate and titanium dioxide after the gold layer, both make increase the sensitivity of the biosensor due to the transfer of free charge between the gold and the dielectric. The obtained results of the comparative study show that the titanium dioxide layer can be a suitable alternative to barium titanate for further increase of the sensitivity of the fiber optic surface plasmon resonance biosensor.

Inverse bremsstrahlung (collisional) absorption of the laser beam is studied in plasma with a generalized (q‐nonextensive) electron velocity distribution and some kind of generalized electron density profile. It is shown that for some values of parameters designating the q‐nonextensive electron velocity distribution function and its generalized density profile, the calculated absorption coefficient reduces to the already known cases with Maxwellian velocity distribution with linear and exponential density profiles.