| Summary: | 碩士 === 國立臺灣師範大學 === 物理學系 === 103 === There are many symmetry objects in the nature, for instance, the flowers, the snowflake and the wheels, which beautiful patterns construct our wonderful world. Laser optics also exist the symmetry laser modes. In the past, those modes generated from the laser cavities by means of setting the optical elements. In this study, we generate the radial symmetry modes using the spatial light modulator (SLM), and analyze the structure and features of laser modes.
Laguerre-Gaussian modes can be generated from the hemi-cylindrical cavities. By means of adjusting the off-axis and pumping size, we can observe the radial symmetry Laguerre-Gaussian superposed modes, so called flower type modes due to its patterns is as beautiful as flowers. In the experiments, we take the SLM as a phase plate to modulate the wavefront of incident beams, and use the SLM as a grating, making the incident beams diffract to generate flower type modes. In the end, we compare the experimental results with numerical patterns in these two methods. Finally, we compare the interference pattern with numerical phase pattern to analyze the structure and the feature of singularity by means of the Mach-Zehnder interferometer.
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