Given a noncompact disconnected periodic curve \(\Gamma \) of infinite length with two components and no self-intersection in \(\mathbb R^3\) , it is proved that there exists a noncompact simply connected periodic minimal surface spanning \(\Gamma \) . As an application, it is shown that for any tetrahedron T with dihedral angles \(\le 90^\circ \) , there exist four embedded minimal annuli in T, which are perpendicular to \(\partial T\) along their boundary. It is also proved that every Platonic solid of \(\mathbb R^3\) contains a free boundary embedded minimal surface of genus zero.