Optical sensors are an important class of sensors. They can offer high sensitivity, high electromagnetic immunity and compactness. An important sub-class is formed by the fiber-optic based sensors. They are used among others for smart structures, where the fiber is used in a distributed sensor configuration. In these systems the light generation and sensing is done in a remote unit. Another sub-class of optic sensors receiving increased attention are the electrooptic integrated sensors. Due to the integration of electronics and optical circuitry on one and the same silicon substrate miniature smart optical sensors can be realized. The price to pay for this marriage between electronics and optics is the loss of electro-magnetic immunity. In this paper we report on the development of a toolbox for electro-optic integrated sensors. Various components, part of the toolbox, like a laser-waveguide coupling, detector-waveguide coupling, optical waveguide structures are briefly discussed. The building blocks are combined in a basic sensor platform, thus showing the maturity of the toolbox approach. By choosing appropriate building blocks from the toolbox, in combination with a specific optical sensor circuit, specialized sensors can be realized.