A conical wave approach to calculating Bessel–Gauss beam reconstruction after complex obstacles

We present an efficient method to accurately calculate the reconstruction properties of a Bessel–Gauss beam after an arbitrary obstruction. Our method makes use of the well-known conical wave features of Bessel–Gauss beams, by considering the projection of the obstacle in space as a result of the travelling conical waves that produce the Bessel–Gauss beams. This approach, of projecting the obstacle boundaries rather than propagating the field itself, results in fast and accurate predictions of the field after any obstacle. We successfully predict the reconstruction properties of a Bessel–Gauss beam after three complex obstacles by calculating the boundaries of the various projected regions. This method has no restrictions regarding the geometry of the obstacle or its placement in the Bessel–Gauss field.