A modular fabrication concept is used to build microoptical systems for commercial application. The concept is based on the fact that microoptical systems can be divided into two functional units, the optical and the electrooptical base plate, which covers active optical elements. In the case of defined interfaces, highly specialized manufacturers can fabricate both components separately. A third company will use these components to build the electrooptical subsystem, which is sold as an OEM system to the system manufacturer. Especially for the component fabrication, the equipment costs can be shared among different applications, which makes the component for each application cheaper. A microoptical distance sensor and a microspectrometer for the near-infrared have demonstrated the concept.