The feasibility of noninterferometric methods to measure phase distribution in a laser beam cross section for visualization of the vortex dislocations of an optical speckle-field wave front is analyzed. Peculiarities of the phase retrieved from the measured intensity distribution (the phase problem in optics) and from the wave-front slopes measured by a Hartmann sensor are discussed. A concept of the vortex and the potential parts of the phase is introduced. An analytic formula to retrieve the potential phase from the measured intensity has been obtained. We show that the considered means of measurements allow the positions of the dislocation centers to be sensed and the spatial configuration of the intensity zero lines to be reconstructed.
© 1998 Optical Society of America
(010.2940) Atmospheric and oceanic optics : Ice crystal phenomena
(010.7350) Atmospheric and oceanic optics : Wave-front sensing
(100.5070) Image processing : Phase retrieval
(120.5050) Instrumentation, measurement, and metrology : Phase measurement
(350.5030) Other areas of optics : Phase
Valerii Aksenov, Victor Banakh, and Olga Tikhomirova, "Potential and Vortex Features of Optical Speckle Fields and Visualization of Wave-Front Singularities," Appl. Opt. 37, 4536-4540 (1998)