Structured illumination for Rayleigh scattering imaging to eliminate the stray light interference

The development of the laser sheet imaging technique is introduced in this paper. This technique is one of the most versatile optical imaging techniques and has been frequently applied in several different domains. However, when applied in limited operating space, the interference from indirect reflections and surrounding backgrounds is known to produce errors in the laser imaging. Therefore, a novel 2D imaging technique named Structured Laser Illumination Planar Imaging (SLIPI) is developed to solve this problem. This method is based on planar laser imaging but uses a sophisticated illumination scheme-spatial intensity modulation-to differentiate between the intensity contribution arising from useful signals and stray light. By recording and dealing with images, the SLIPI method can suppress the diffuse light and maintain the useful signals. In this paper, we first use the MATLAB software to simulate the SLIPI method, and the conclusions suggest that the stray light interference can be removed effectively. Furthermore, the SLIPI apparatus, consisted of the continuous laser, Ronchi grating and EMCCD camera is designed. And the Ronchi grating is used to produce the sinusoidal distribution of the laser sheet. At last, SLIPI apparatus is combined with the Rayleigh scattering approach in the McKenna flat burner to generate the Rayleigh scattering signal. And the thesis presents convincing experimental evidence that the SLIPI method is able to remove the diffuse light contribution, thus improving and enhancing the visualization quality.