| Description: | [DPS Colloquium] Prof. Bipul pal (DPS, IISER Kolkata) -- Everybody can do some nonlinear optics |
| Date: | Wednesday, Mar 04, 2020 |
| Time: | 2:30 p.m. - 4 p.m. |
| Venue: | Meghnad Saha Lecture Theatre |
| Details: | Nonlinear optics deals with the domain where materials' response is nonlinear in electric field of incident light. This arises from anharmonicity in the electronic motion under extremely high electric field distorting the electron-nuclear Coulomb potential. Common notion is that study of nonlinear optical phenomena requires high intensity pulsed laser system, accessible only to some of the sophisticated research labs. In this talk I shall discuss some simple techniques of studying nonlinear refraction using simple low power diode lasers, which is accessible even to the high school students. The techniques rely on the resonance enhancement of nonlinear response by choosing the laser wavelength close to an absorption peak of the material used. The observed nonlinearity belongs to thermal nonlinear response arising from anharmonicity in the atomic/molecular motion. Thermal nonlinear optical coefficients can be several orders of magnitude higher than the electronic nonlinear optical coefficients. |
| Calendar: | Seminar Calendar (entered by anandamohan) |