  In this paper, we construct simply connected symplectic Calabi-Yau
6-manifolds by applying Gompf's symplectic fiber sum operation along $T^4$.
Using our construction, we also produce symplectic non-K\"{a}hler Calabi-Yau
6-manifolds with fundamental group $\Z$. In this paper, we also produce the
first examples of simply connected symplectic Calabi-Yau and non-Calabi-Yau
6-manifolds via coisotropic Luttinger surgery.
