Multiple Beam Interferometry for Third Order Optical Nonlinearity

Tasnim, Md Mohiuddin

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Multiple Beam Interferometry for Third Order Optical Nonlinearity, A Dissertation Submitted to the Department of Physics as a Partial Fulfillment of the Requirement for the Degree of M. Phil. in Physics. (10.66Mb)

Date

2017-08

Author

Tasnim, Md Mohiuddin

Abstract

An experimental research work has been done to estimate the nonlinear refractive index of 2, 5 - dimethylaniline (DMA) by multiple (three) beam interferometry using a Mach-Zehnder interferometer. 2, 5 - dimethylaniline was dissolved in Methanol to increase the optical transparency. Five different concentrations (V/V) of 2, 5 - dimethylaniline was used in the experiment which are 1:3, 1:6, 1:9, 1:12 and 1:15. A continuous wave argon ion (Ar-ion) laser which emits radiation at 457 nm, 488 nm and 514 nm, was used to initiate the optical nonlinearity in the sample. This technique gives a result of a negative value for n2 for DMA having a magnitude of the order of 10-6 cm2/W.