Statistical properties of GB speckle patterns: Influence of the phase modulation depth of the synthesized GB apertures

Background and Objectives: Results of theoretical studies of the statistical properties of gene-based speckle patterns are presented. These gene-based (GB) speckle patterns visualize digital versions of genetic structures of biological objects under investigation. The reported study was the focused on influence of the depth of phase modulation of a collimated coherent beam used to read information from a synthesized GB phase screen. Materials and Methods: In the modeling, the nucleotide sequence of the target gene B602L of the causative agent of African swine fever (the HuB20 strain) was used to synthesize a model GB phase screen. The procedure was based on establishing a correspondence between the unique number of each codon (triplet) in the sequence, which is in the range between 0 and 63, and the depth of phase modulation of the readout beam by the related pixel in the synthesized GB-aperture. After that, the random spatial distribution of the speckle intensity in the Fraunhofer diffraction zone was calculated. The obtained model data were compared to similar data for phase screens with Gaussian and uniform distributions of local phase shifts. Results: It has been found that the synthesized GB speckle pattern, in contrast to the simulated speckle patterns for Gaussian and uniform distributions of local phase shifts in speckle-generating phase screens, is characterized by significant oscillations of the coherent component of the speckle field with the increasing phase modulation depth. This is caused by featured statistical properties of the codon ensemble in the processed nucleotide sequence of the target gene of the HuB20 strain. The original model data on the sensitivity of the synthesized GB fields to mutation-driven codon substitutions in the original sequence for the target gene of the HuB20 strain are presented. Conclusion: As the result, the original model data on the sensitivity of synthesized GB speckle patterns to mutation-induced codon substitutions in the initial sequence for the target gene of the HuB20 strain have been presented.