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In the first part of this study we analyse the spatial evolution of the spectrocopic esponse of quasiparticles in diffusive S-N and in S-S? junctions . We show that a combination of the Usadel theory with P(E) DCB approach is enough to describe precisely the quasiparticle excitation spectrulm even in the case of moderately strong correlations. In the second part of this study we created lateral S-N-S junctions and examined their response to the magnetic field. In zero-field we found a mini-gap induced in N by proximity with S. In the presence of a magnetic field, we mapped the evolution of mini-gap inside proximity Josephson junctions. Unexpectedly, we observed Josephson vortices and discovered that they have real cores, in which the proximity gap is locally suppressed and the normal state recovered. By following the Josephson vortex formation and evolution in the applied magnetic field, we demonstrate that they originate from quantum interference of Andreev quasiparticles, and that the phase portraits of the two superconducting quantum condensates at edges of the junction decide their generation, shape, spatial extent and arrangement. Our observation opens a pathway towards the generation and control of Josephson vortices by applying supercurrents through the superconducting leads of the junctions, that is, by purely electrical means without any need for a magnetic field - a crucial step towards high-density on-chip integration of superconducting quantum devices.