ABSTRACT
The photonic bands exhibited by extrinsic plasma photonic crystal using a bulk magnetized cold plasma have been discussed. The periodicity as left-hand and right-hand polarizations arises in the cold plasma due to negative and positive values of external magnetic field, respectively. Band structure and reflectance of the induced periodic plasma crystal, using the well-known simple transfer matrix method (TMM), are theoretically analyzed by varying the parameters such as angle of incidence, applied magnetic field strength, electron density, and layer thicknesses ratio. It is observed that the high reflectance frequency ranges in GHz and photonic bandgaps observed from the band structures are in good agreement. The photonic bandgap increases with increase in the incident angle, and thereafter a new band appears near the plasma frequency as the incident angle is increased to 30°, where the appearance of new gap for TM polarization at oblique incidence is attributed to the Bragg’s interference of plasma layers. If we increase the applied magnetic field strength, the photonic bandgap decreases, where shifting in the lower band edge is more significant compared with the higher band edge. Furthermore, it is found that the photonic bandgap increases with increase in the electron density and again the lower band edge is more sensitive in comparison with the higher band edge. On increasing the thickness ratio, the band gap decreases and shows a red shift, whereas there is a reverse effect vice versa, that is, on decreasing the thickness ratio (less than 1), the photonic bandgap becomes narrower and is shifted toward the higher frequency showing the blue shift. These observed results can be used in designing a tunable broadband reflector or filter in the desired GHz frequency range and may be very useful in fabricating photonic devices.
