TITLE : Nonlinear Optics: Fundamentals and Applications


Nonlinear optics (NLO) refers to the study of the interaction of strong light fields with matter. The advent of Nonlinear Optics was in 1875 with the discovery of the Kerr effect (quadratic electro-optic effect), which was followed by that of the Pockels effect in 1893 (linear electro- optic effect). In 1960 Franken and colleagues observed second harmonic generation (SHG) of ruby laser light in a quartz crystal. Subsequently, Bloembergen and colleagues formulated a general theoretical framework for three- and four- wave mixing at optical frequencies. Second order nonlinearities mostly involve optical frequency conversion while third order phenomena include nonlinear phase modulation, absorption, refraction and scattering of light. In addition to facilitating a deeper understanding of light-matter interaction, NLO has also provided solutions for several modern engineering problems. For instance, one of the major applications of NLO is the frequency conversion of laser light. Similarly, optical nonlinearity can be utilized for realizing many key-devices in the telecom industry such as switches, routers, and wavelength converters. Nanoparticles and nanocomposites have entered the realm of nonlinear optics in recent years because of phenomena such as quantum confinement of electrons and holes in semiconductor quantum dots, excitation of surface plasmon resonances (collective oscillation of free electrons) in metal nanoparticles, etc. In this talk we will discuss the physical origins of optical nonlinearity in material media, and overview the nonlinear optical properties exhibited by some materials. Major experimental techniques for the determination of second and third order nonlinearities will be explained. Some interesting results obtained from the research work carried out in our lab will be presented.


Speaker: Prof. Reji Philip

Venue: A4 Conference room

Date and Time: February 18th, 2022, 4:00 pm