Kaiser H.-Ch., Neidhardt H., Rehberg J On one dimensional dissipative Schr\"odinger-type operators, their dilations and eigenfunction expansions (221K, Postscript) ABSTRACT. We study in detail Schr\"odinger-type operators on a bounded interval of $\bR$ with dissipative boundary conditions. The characteristic function of this operator is computed, its minimal self-adjoint dilation is constructed and the generalized eigenfunction expansion for the dilation is developed. The problem is motivated by semiconductor physics.