چكيده به لاتين
In the recent decays, surface plasmon polariton (SPP) waves are intruduced as a promising solution to realize ultra-dense integrated optical circuits, without suffering from limitations of classical diffraction limit of light in the conventional photonic components. Accordingly, until now, several plasmonic devices have been proposed, such as filters, sensors, antennas, etc. Switches and also sensors as two key components in the field of optical communications have attracted many attentions. Hence, in this thesis, firstlly, a compact elector optical (EO) plasmonic switch with high transmission, low required external voltage for switching and simple geometry for fabrication is proposed. The proposed structure was consist of a MIM bus waveguide directly coupled to two drop cavities as well as two reflector nanocavities. All the cavities were filled with EO material. Based on single and double reflector cavity structures, two plasmonic 1×2 switches at the wavelengths 984nm and 1560nm are proposed. Besides, a novel implementation for plasmon-induced transparency (PIT) composed of a bus waveguide coupled to a rectangular nanocavity and an H-shape resonator is proposed. In this device, for avoiding oxidization of the structure, a thin graphene layer on the inner walls of the H-resonator is employed and the effect of it is studied. It is observed that the proposed structure can be used as a nanosensor with a refractive index sensitivity of 1300nm.RIU-1 and figure of merit equal to 59.1 RIU-1 and also as a compact nanoswitch with transmission 76% and a modulation depth equal to 19.77dB. Another PIT tuned structured composed of a bus waveguide coupled to a nanodisk and two internally tangent disks (TITD) is proposed. There, it is shown that the PIT peak can be tuned from 782nm to 815nm using an external pump laser with an intensity of up to 24.39 MW/cm2 (Power≅2mW). The TITD-based structure can be well employed as a nanosensor, with a refractive index sensitivity and figure of merit equal to 690nm.RIU-1 and 49.28 RIU-1 respectively.
In addition to the above mentioned, with the development of terahertz (THz) technology, and appearing various applications of this technology in spectroscopy, communication, slow light, and monitoring of biomaterials, an ultra-compact double 8-shaped plasmonic structure consists of a semiconductor-insulator-semiconductor (SIS) bus waveguide coupled to dual disk resonators for realization of PIT in the THz region has been studied. Indium antimonide (InSb) was employed to excite SPP in terahertz region. In this stricture, the sensitivity equal to 654 GHz/RIU-1 was be obtained for single PIT structure. It is shown that, a frequency shifts equal to 37 GHz and 99 GHz could be observed for the denatured and the hybridized DNA states, respectively. In the final, by appearing various applications in the mid-infrared (MIR) band, such as health-related fields, sensing, industrial process and security applications, a novel silicon-based integrated structure consists of a semiconductor-insulator-semiconductor (SIS) plasmonic bus waveguide coupled to three rectangular nano-cavities for PIT and plasmon-induced absorption (PIA) effects in MIR band is proposed. It is shown that the proposed structure can be used either as a temperature sensor with a sensitivity of 1.48 nm/°C or as a plasmonic switch operating in the MIR range with transmission 83% and modulation depth of 20.74dB
