We present an inherently phased synthetic aperture microscopy method to mitigate speckle noise and frame- phasing-related issues affecting existing systems that employ coherent illumination for maximum phase sensitivity. Instead of digital holography, our method uses a vibration-insensitive, common-path, phase-shifting shearing interferometer to detect the phase gradient vector and the amplitude of the optical field at the image plane of the microscope. The stability of the speckle field seen by the sensor allows coherent speckle compensation. For demonstration, we show speckle-free super-resolved reconstructions of polystyrene beads in index matching microscope oil.
An interferometric set-up able to measure angles as large as +180 degree(s) is presented. The principle of the method is to measure a linear displacement (translation) produced by a crank-gear mechanism which converts the angular movement of a rotating table. The optical scheme and consideration on the accuracy of the method are presented.
The measurement of large angles is still an actual problem in metrology. Interferometric methods based on Michelson interferometer have high sensitivities, precision and accuracy but the angular range is limited. Two methods are presented: hollow roof prism on a rotating table and a plane-parallel plate in the interferometer's arm, as systems for angular measurements.
Complex refractive index determination (refractometry) of metals can be made successfully with methods using reflectivity measurements. In this paper a brief classification of reflectivity methods with subsequent comments about their sensitivity is made. Experimental results obtained using the most suitable methods are presented.