Seminar & WorkshopsSeminar:Quantum optics is a field which uses quantum mechanical physics to investigate phenomena involving light and its interactions with matter. According to quantum theory, light may be considered not only as an electro-magnetic wave but also as a "stream" of particles called photons. These particles should not be considered to be classical billiard balls, but as quantum mechanical particles described by a wavefunction spread over a finite region. The theory that light moved in discrete bundles (i.e. photons) was presented in Max Planck's 1900 paper on the catastrophe in black body radiation. In 1905, Einstein expanded on these principles in his explanation of the photoelectric effect to define the photon theory of light. Each particle carries one quantum of energy, equal to hν, where h is Planck's constant and ν is the frequency of the light. That energy possessed by a single photon corresponds exactly to the transition between discrete energy levels in an atom (or other system) that emitted the photon; material absorption of a photon is the reverse process. Einstein's explanation of spontaneous emission also predicted the existence of stimulated emission, the principle upon which the laser rests Lasers are the most obvious application of quantum optics .Other remarkable results are the demonstration of quantum entanglement, quantum teleportation, and quantum logic gates. The latter are of much interest in quantum information theory       |
