Precise optical registration of fine-structured electrical sparks and related challenges.

Fine-structured sparks naturally formed in electrical gas discharges are challenging objects of optical research. The veracity of the spark structure image obtained by laser probing techniques is still a subject for discussion due to possible distortions introduced by the employed optical setup. We thoroughly analyze this issue by simulating the spark image formation and evaluating the effect of the setup response function on the spark pattern quality.

Extraction of high-contrast diffraction patterns of fine-structured electrical sparks from laser shadowgrams.

The fine-structured electrical spark is a complex gas discharge phenomenon, which appears as a cluster involving dozens of closely-packed thin plasma filaments that can be revealed by laser shadowgraphy. However, the immense complexity of the spark, together with the features of laser imaging, challenges the spark image processing. Herein, we developed an image processing procedure, providing outstanding shadowgram denoising while preserving the spark image capacity.