Semiconductor quantum wells and their band gap resonant nonlinear optical properties have been shown to be important because of their potential for applications in optical switching and signal processing. The near band gap optical properties of quantum well structures are dominated by strong excitonic effects due to quantum confinement. There is much interest in the use of optical devices as MQW for performing all optical switching or by using electrostatic field to change the absorption directly by driving electrons in the QW structure. Such effects are able to produce a family of optical logic elements. In this paper, we present the linear and nonlinear optical properties seen in III-V (GaInAs/InP) multi quantum well structures. The nonlinear properties associated to the absorption saturation of the heavy hole excitons are demonstrated. We review the applications of these nonlinear processes in the field of the 2D and integrated optics (intrinsic bistability and nonlinear coupler) Etude des caracteristiques de transmission optique et mise en evidence d'effets non lineaires associes a la saturation d'absorption excitonique; applications (bistabilite intrinseque, coupleur optique)