vicinity of the points of $0-$ to $\pi -$ transitions, $d_{Fn},$ and for large $d_{F}$ values and high exchange fields $H.$ In this mode (see Fig. \[Phase\]) the weak place shifts to sFS part of SIsFS device and the structure transforms into a conventional SFS-junction with complex SIs electrode.

In the first approximation on $\Gamma /(\beta \Gamma _{BI})\gg 1$ it follows from (\[Jsymm1\]), (\[EqForKhi1\]) that $$\chi =\frac{\Gamma _{BI}}{\Gamma }\frac{\beta \sin \left( \varphi \right) }{1-\beta \cos \left( \varphi \right) },$$resulting in $$J_{S}(\varphi )=\frac{J_{G}\beta }{\Gamma \left( 1-\beta \cos \varphi
\right) }\left( \sin \varphi -\frac{\Gamma _{BI}}{2\Gamma }\frac{\beta \sin
(2\varphi )}{\left( 1-\beta \cos \varphi \right) }\right) .
\label{SInFSotFI}$$The shape of CPR for $\chi \rightarrow 0$ coincides with that previously found in SNS and SFS Josephson devices [Ivanov]{}. It transforms to the sinusoidal form for sufficiently large thickness of F layer. For small thickness of the F-layer as well as in the vicinity of $0-\pi $ transitions, significant deviations from sinusoidal form may occurred.

Transition between the *mode (1a)* and the *mode (1b)* is also demonstrated in Fig.\[Ic\_ds\]. It shows dependence of critical current $J_{C}$ across the SIsFS structure versus F-layer thickness $d_{F}.$ The inset in Fig.\[Ic\_ds\] demonstrates the magnitude of an order parameter at 