This chapter discusses the method of polarization mapping and analysis of DNA-associated symbolic sequences obtained as a result of sequencing DNA fragments. In the method, the symbolic sequence is displayed using a multi-element phase screen with a dimension determined by the length of the sequence. The encoded units in the sequence are triplets combining different quantities (from 0 to 3) of the symbols A, C, T, G, corresponding to the four basic nucleotides (adenine, cytosine, thymine, guanine). Each triplet is represented in the phase screen by a 2 × 2 submatrix; the positions of the elements in the submatrices correspond to a certain (A, C, T, G) nucleotide, and the values of the elements determine the content of a given nucleotide in the triplet. The phase-modulating screen synthesized in this way is then read by a collimated laser beam with a given polarization state, resulting in the formation of a polarization-dependent speckle pattern in the focal plane of the Fourier transform lens. This pattern uniquely displays information about the structure of the analyzed symbolic sequence, which can be considered in terms of spatial distributions of the normalized local values of the Stokes vector in the diffracted light field. Discrimination of local values of the third and fourth components of the Stokes vector using cutoff thresholds close to ±1 allows one to obtain binary “fingerprints” of the analyzed sequences, which are very sensitive to single nucleotide substitutions of nucleotides. The results of verification of the discussed method using symbolic sequences corresponding to various strains of the SARS-CoV-2 virus are presented. A comparison of the results of polarization mapping with the data obtained using the chaos game representation (CGR) popular in bioinformatics showed the advantage of the polarization method in terms of minimizing the size of the resulting mappings and sensitivity to nucleotide substitutions.