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Light is undoubtedly one of the most fascinating and fundamental phenomenon in this universe. Light waves can not only travel through vacuum but also define the maximum speed that any object can attain in our universe. It was an investigation of the nature of light that led to all of modern physics. In some sense, light is also the source of life on our planet.
If Newton rose to fame standing on the shoulders of giants, Einstein rose to fame riding on wings of a photon. Below is a list of interesting EM topics and some related online material. |
| Sl. | Topic | Online Resources |
| 1 |
Electromagnetics and its role in modern technologies
Medical applications like imaging (CT Scanning, MRI, fMRI, EEG, etc) Wireless communications, cell phones, active sensors and devices Night vision cameras, radars and security monitoring Plasma technologies and nuclear fusion |
How does fMRI brain scanning work? EEG and Action Potentials How does a CT scan work? How do cell phones work? How does night vision work? |
| 2 |
Sources of light and Wave-Particle Duality Light is produced by various kinds of sources, some of which are natural and some artificial. The properties of light can vary a lot depending on the process of its generation. Also, sometimes light seems to behave like a wave and sometimes like a particle (photon). Which of these two aspects manifests in a given situation depends on the property of light being measured. |
How LASERs work! LASER fundamentals How modern light bulbs work What is the wave/particle duality? Feynman on wave particle duality What is light made of? |
| 3 |
Maxwell's equation and Einstein's theory Maxwell's equations gave rise to Lorentz transformations which in turn gave rise to Einstein's theory of relativity which is the bedrock of all of what we call modern physics. |
Maxwell's equations - The mechanical universe Maxwell's equations - Basic derivation Introduction to the Lorentz transformation How special relativity makes magnets work |
| 4 |
Simplification of Maxwell's equations for antenna problems
The four Maxwell's equations can be reduced to a set of two equations which are very helpful in solving for the electromagnetic fields generated due to time-varying charge and current configurations. |
Vector Magnetic Potential |
| 5 |
Snell's law, total internal reflection and evanescent waves
Snell's laws governs the reflection and refraction of light incident on dielectric surfaces. If the angle of incidence is larger than the critical angle, the refracted wave becomes evanescent in nature and this phenomenon is called Total Internal Reflection (TIR). Flow of EM energy as evanescent waves created due to TIR has important applications in optical fibers and plasmonics. |
Fundamentals of Evanescent Waves |
| 6 |
Origin of permittivity and conductivity of materials
Simple models of atomic polarization due to electric fields can be used to find analytical expressions for the frequency dependennce of permittivity and conductivity. |
Lorentz and Drude Models |
| 7 |
Plasma science and Nuclear Fusion
A plasma is a gas of charged particles and called the fourth state of matter. 99% of the visible universe is composed of plasmas! Study of its properties and mechanisms of confinement is a very important area of research. One such confinemt mechanism called the tokamak is used in nuclear fusion and can perhaps solve our energy problem in the future. |
Where does the sun get its energy ITER : The world's largest fusion experiment Plasma Displays : Working and Utility Overview of Tokamaks |
| 8 |
Surface plasmon wave and its applications
Surface plasmons are electromagnetic waves flowing on the interface of metals and dielectrics. These have several applications in communications, sensors, solar cells and infrared imaging. |
Plasmonic Solar Cell Biosensors for Cancer Detection Surface Plasmon Based Biosensors |
| 9 |
Role of electromagnetics in vision, cameras and photography
Cones and rods in our eye are responsible for vision, which is nothing but detection and manipulation of EM waves. A camera also works by a similar principle and uses photo-diodes (pixels) arranged in a 2D array. Polarization of EM waves also plays an important role in vision and photography. |
Color Sensing in Camera Systems Structure and Working of Human Eye |