Laser studies of internal conical diffraction 1 Quantitative comparison of experimental and theoretical conical intensity distribution in aragonite*

Detailed measurements of the conical intensity pattern aragonite have been carried out with an incident Gaussian beam (TEM00) of a helium neon laser. Quantitative agreement with theoretical calculations is found. It is shown that the integrated intensities on either side of the Poggendorff dark circle are not equal, unless the far-field condition for Fraunhofer diffraction is satisfied.