<p> At present modulators in communications industry utilize non-linear materials like indium tin oxide (ITO) and DLD-164 as a dielectric, which makes the fabrication process cumbersome and expensive. This thesis discusses the possibility of using only gold and air as conductor and dielectric to characterize a signal modulating device. Both electro-absorption modulation (EAM) and phase change driven modulation is possible with the design. For the change in phase a length of 2.992 µ<i>m</i> for the modulating arm of a Mach-Zehnder modulator (MZM) was achieved for operation at 525 <i>nm</i>. High absorptions of electromagnetic (EM) waves was seen at the 480 <i>nm</i> mark allowing a length of just 4.95 µ<i>m</i> for EAM. The results suggest that an all plasmonic noble metal modulator utilizing air as a dielectric is possible for operation in the visible 400 <i>nm</i> to 700 <i>nm</i> range. The concept is supported by proof-of-principle based simulations. </p><p> This thesis proposes a novel idea of an all plasmonic modulator driven by changes in free carrier concentration in gold and surface plasmon polariton (SPP) excitations under an applied potential. The prototype model is simulated using a commercial finite difference time domain solver. The simulation enviro<i> nm</i>ent allows Maxwell’s equations to be solved in the time domain to investigate light propagation and absorption characteristics under an externally applied electric potential. The free carrier concentration dependent permittivity of gold is exploited to investigate possible applications in nano-photonics and optical communications.</p><p>
| Identifer | oai:union.ndltd.org:PROQUEST/oai:pqdtoai.proquest.com:10978327 |
| Date | 25 April 2019 |
| Creators | Sharma, Sumeet |
| Publisher | California State University, Long Beach |
| Source Sets | ProQuest.com |
| Language | English |
| Detected Language | English |
| Type | thesis |
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