  Using the Ginzburg-Landau theory extended to the next-to-leading order we
determine numerically the healing lengths of the two order parameters at the
two-gap superconductor/normal metal interface. We demonstrate on several
examples that those can be significantly different even in the strict domain of
applicability of the Ginzburg-Landau theory. This justifies the use of this
theory to describe relevant physics of two-gap superconductors, distinguishing
them from their single-gap counterparts. The calculational degree of complexity
increases only slightly with respect to the conventional Ginzburg-Landau
expansion, thus the extended Ginzburg-Landau model remains numerically far less
demanding compared to the full microscopic approaches.
