Research Topic: A Study on the Generation of Custom Designed Beams and their Propagation Characteristics for Adaptive Optics

Outline:

PhD work is focused on the generation and propagation of custom designed beams through atmospheric turbulence. The work involves the numerical simulation with experimental validation. The main findings of my research work are as follows:

• The study involves effects of atmospheric turbulence on the propagation of the laser beam. The Zernike polynomial and Fourier transform based turbulence phase screen model is realised to simulate the turbulence phase screen of known strength, also, turbulence of various strengths are generated and characterized, experimentally, in the laboratory by the various type of turbulence generators.
• Evolution of phase singularities is demonstrated in the propagating wavefront under severe turbulence condition, numerically; also a novel interferometric optical setup is demonstrated for the affirmation of phase singularities generation in the wavefront using the turbulence cell.
• Generation and propagation of Gaussian beam array are studied in numerical simulation followed by the experimental validation.
• The new types of beams are designed and generated in which singular phases are encoded at multiple locations and are termed as Custom Designed Beams (CDBs). Generation and their propagation have been studied numerically as well as experimentally in free space and also in the presence of turbulence.
• The effect of atmospheric turbulence on the propagation of five groups of CDBs has been investigated with the help of two types of turbulence simulators (such as ATS and the turbulence cell) along with the actual propagation effects of turbulence in the field up to 200m. The effectiveness of these beams is demonstrated by analysing the PSF spreading and the scintillation index.