condition that the currents flowing across Is and sF interfaces should be equal to each other.

For large thickness of the middle s-electrode ($d_{s}\gg d_{sc}$) the magnitude of order parameter $\delta _{s}(-d_{s})$ is close to that of a bulk material $\Delta _{0}$ and we may put $a=-b$ in Eqs.(\[delta1(0)\]) and (\[delta1(df)\]) $$\delta _{S}(d_{F})=\delta _{s}(0)=\frac{\sqrt{2}\Delta _{0}}{\Gamma \left(
\left( p+q\right) -\left( p-q\right) \cos \left( \varphi -\chi \right)
\right) },  \label{Aeqb1}$$resulting in $$J_{S}(0)=J_{S}(d_{F})=\frac{J_{G}\beta \sin \left( \varphi -\chi \right) }{\Gamma \left( 1-\beta \cos \left( \varphi -\chi \right) \right) }
\label{Jsymm1}$$together with the equation to determine $\chi $ $$\frac{\Gamma }{\Gamma _{BI}}\sin \left( \chi \right) =\frac{\beta \sin
\left( \varphi -\chi \right) }{1-\beta \cos \left( \varphi -\chi \right) },~\beta =\frac{p-q}{p+q}.  \label{EqForKhi1}$$

From (\[Aeqb1\]), (\[Jsymm1\]) and (\[EqForKhi1\]) it follows that in this mode SIsFS structure can be considered as a pair of SIs and sFS junctions connected in series. Therefore, the properties of the structure are almost independent on thickness $d_{s}$ and are determined by a junction with smallest critical current.

Indeed, we can conclude from (\[EqForKhi1\]) that the phase $\chi $ of s layer order parameter depends on the ratio of the critical current, $I_{CSIs}\varpropto \Gamma _{BI}^{-1},\ $of its SIs part to that, $I_{CsFS}\varpropto |\beta |\Gamma ^{-1},\ 