Mr. Reza Masoudian Saadabad, Dr. Naser Hatefi-Kargan,
Volume 9, Issue 1 (International Journal of Optics and Photonics (IJOP) Vol 9, No 1, Winter-Spring 2015)
Abstract
In this paper a resonant tunnelling quantum well infrared photodetector (RT-QWIP) is discussed. Each period of this photodetector structure comprises of a resonant tunnelling structure (AlAs/AlGaAs/AlAs) nearby a quantum well (AlGaAs/GaAs). In this photodetector, photocurrent is produced when an electron makes a transition from the ground state of the well to an excited state which is coupled to the resonant state of the resonant tunnelling structure. The effect of structural parameters of the photodetector on the electronic states and oscillator strength of transitions between energy subbands of the structure is investigated. Then using the obtained results, an appropriate structure for the RT-QWIP is determined which exhibits a photoresponse peak at 7.3 μm at 77 K.
Naser Hatefi-Kargan, Milad Zare-Zardini,
Volume 12, Issue 1 (International Journal of Optics and Photonics (IJOP) Vol 12, No 1, Winter-Spring 2018)
Abstract
In this paper the transmittance of metal-insulator-metal (MIM) waveguides containing semi-circular ring shaped and rectangular ring shaped grooves are investigated. By varying groove parameters their effects on the transmittance of the MIM waveguides are investigated. The results show that the transmittance spectra of the waveguides have maximum and minimum points, and by using appropriate parameters for the grooves it is possible to make the transmittance maximum or minimum at a required frequency. Therefore by using the ring shaped grooves in the MIM waveguides a frequency splitter is designed. In comparison the efficiency of a MIM waveguide containing the ring shaped groove, on blocking the transmission of a required frequency, is higher than the efficiency of a MIM waveguide containing tooth shaped groove.
