  Speckle patterns are formed by random interferences of mutually coherent
beams. While speckles are often considered as an unwanted noise in many areas,
they also formed the foundation for the development of numerous speckle-based
imaging, holography and sensing technologies. In the recent years, artificial
speckle patterns have been generated with spatially incoherent sources using
static and dynamic optical modulators for advanced imaging applications. In
this report, a fundamental study has been carried out with Bessel distribution
as the fundamental building block of the speckle pattern: speckle patterns
formed by randomly interfering Bessel beams. Indirect computational imaging
framework has been applied to study the imaging characteristics. In general,
Bessel beams have a long focal depth, which in this scenario is counteracted by
the increase in randomness enabling tunability of the axial resolution between
the limits of Bessel beam and a Gaussian beam. Three-dimensional computational
imaging has been synthetically demonstrated. The presented study will lead to a
new generation of incoherent imaging technologies.
