of tunnel barrier $(\gamma _{BI}=1000)$ the suppression of superconductivity in the left electrode is negligibly small. This allows one to select the thickness of the left S electrode $d_{SL}=2\xi _{S}$ without any loss of generality. On the contrary, proximity of the right S electrode to the F layer results in strong suppression of superconductivity at the FS interface. Therefore the pair potential of the right S electrode reaches its bulk value only at thickness $d_{SR}\gtrsim 10\xi _{S}.$ It is for these reasons we have chosen $d_{SR}=10\xi _{S}$ for the calculations.

Furthermore, the presence of a low-transparent tunnel barrier in the considered SIsFS structures limits the magnitude of critical current $J_{C}$ by a value much smaller compared to a depairing current of the superconducting electrodes. This allows one to neglect nonlinear corrections to coordinate dependence of the phase in the S banks.

The results of calculations are summarized in Fig.\[Del\_ArbT\]. Figure [Del\_ArbT]{}a shows the dependence of $J_{C}$ of the SIsFS structure on the F-layer thickness $d_{F}$ for relatively large $d_{s}=5\xi _{S}$ (solid) and small $d_{s}=0.5\xi _{S}$ (dashed) s-film thickness. The letters on the curves indicate the points at which the coordinate dependencies of the magnitude of the order parameter, $|\Delta (x)|,$ 