Part I: The impulse response for modified apertures and resolution in microscopy ----- 4 Chapter 1. Resolution in microscopy and defect of focus with modulated apertures -------- 5 Chapter 2: Linear aperture----------------------------------------------------------------------------- 17 Chapter 3: pupils with radially transmission r n distribution---------------------------------------22 Chapter 4: Linear - quadratic aperture --------------------------------------------------------------- 34 Chapter 5: Hamming aperture ------------------------------------------------------------------------- 49 Chapter 6: Longitudinal strips inside the circular aperture ---------------------------------------- 62 Chapter 7: Deformed cardiac and elliptical apertures ---------------------------------------------- 76 Chapter 8: A new model of modulated aperture ---------------------------------------------------- 86 Part II: Formation of speckle images using modulated apertures -------------------------- 100 Chapter 9: Speckle images formed by diffusers using conical and linear apertures --------- Chapter 10: Recognition of direction of new apertures from the elongated speckle images --- Chapter 11: Speckle images modulated by a new Hamming- linear aperture----------------- Chapter 12: Speckle images using Gaussian and graded - index apertures -------------------- Chapter 13: Contrast of speckle images using modulated apertures ---------------------------- Part III. Application on confocal laser microscope Chapter 14: Design of a Cascaded Black-Linear Distribution (CBLD) in circular aperture -Application on Confocal Scanning Laser Microscope ------------------------------------------ Chapter 15: A hyper- resolving polynomial aperture and its application on confocal microscope Chapter 16: A study on misaligned linear and quadratic apertures in Confocal Scanning Laser Microscope (CSLM) -----------------------------------------------------------------------------------.