ECS422/622 : Plasma and Plasmonics
Kushal Shah

Grading Scheme : 30 Mid-Sem, 40 End-Sem, 30 Assignment

Plasma is usually called the fourth state of matter and is mainly a gas of charged particles. It is not only of deep theoretical interest in physics, but also offers immense applications from fabrication processes in the semiconductor industry to stealth technology for airplanes. Though the equations governing neutral gas dynamics are applicable for plasma modeling, the properties of a plasma are very different from that of a gas and lot more interesting, due to the presence of charged particles.

Surface Plasmons (SP) are coherent electromagnetic oscillations that exist at the interface between a dielectric and a metal, in the range of frequencies when the permittivity of the metal becomes negative. In this frequency range, the dielectric properties of the metal electrons mimic that of a quasi-neutral plasma. These plasmons can propagate along such an interface until the electromagnetic energy is dissipated. The primary aim of plasmonics is to exploit the optical properties of metallic nanostructures to enable active manipulation of light at the nanoscale. The natural compatibility of plasmonics with electronics also offers a lot of promise for next-generation systems that will incorporate the best qualities of both photonics and electronics for communication at much higher speeds than what is possible today. A plasmonic device based on negative index materials (NIMs) is also thought to be able to help in constructing a superlens that can exceed the diffraction limit. NIMs are basically artificial structures where the refractive index has a negative value leading to an unnatural deviation of light during refraction when it is incident on to a NIM from a positive index material.

This course is going to cover the theoretical aspects of plasmas, plasmonics and negative index materials with a few lectures on computer simulations using FDTD.

Broad outline for the course:
  1. Maxwell's equations (Ch. 7,9 of Griffiths)
  2. Dispersion Model (Sec. 7.5 of Jackson)
  3. Evanescent Waves
  4. Plasma Kinetic Theory
  5. Plasma Fluid Dynamics
  6. Linear Plasma Waves
  7. Scattering and Diffraction
  8. Surface Waves in Dielectrics
  9. Surface Plasmons (SP)
  10. Negative Index Materials (NIMs) (Veselago 1968, Ch. 1-2 of Marques, Ramakrishna 2005)
  11. FDTD method (Ch. 2, 4, 9 of Taflove&Hagness, MEEP)

Recommended books and papers: