RESUMEN
Light scattering by disordered media is a ubiquitous effect. After passing through them, the light acquires a random phase, masking or destroying associated information. Filtering this random phase is of paramount importance to many applications, such as sensing, imaging, and optical communication, to cite a few, and it is commonly achieved through computationally extensive post-processing using statistical correlation. In this work, we show that mixing noisy optical modes of various complexity in a second-order nonlinear medium can be used for efficient and straightforward filtering of a random wavefront under sum-frequency generation processes without utilizing correlation-based calculations.
RESUMEN
By considering parity-defined Laguerre-Gaussian (LG) and Hermite-Gaussian (HG) beams as input modes, we present arguments through experimental and theoretical results in order to affirm that using HG modes as bases is more suitable for optical mode conversion than using LG modes. By analyzing the normalized overlap integral and the generated modes, we determine a clear rule for the dominant mode for nonlinear mixing of HG beams, while the same is not possible for LG beams. In addition, examples of optical modal conversion using both HG and LG modes as input beams are demonstrated.
RESUMEN
We establish a correlation rule of which the value of the topological charge obtained in intensity correlation between two coherence vortices is such that this value is bounded by the topological charge of each coherence vortex. The original phase information is scrambled in each speckle pattern and unveiled using numerical intensity correlation. According to this rule, it is also possible to obtain a coherence vortex stable, an integer vortex, even when each incoherent vortex beam is instable, non-integer vortex.