The overall goal of this research project is to develop new techniques for the monolithic integration of electronic and optical waveguide devices in the SOI platform. We have focused on designing and demonstrating monolithic integrated waveguide photodetectors and transimpedance amplifiers since these components will be vital to most systems. In the absence of a commercial foundry SOI technology offering conventional CMOS electronic devices integrated with photonic components, we have taken two different approaches towards the integration of amplifiers and photodetectors. First, we implemented lateral bipolar junction transistors (LBJTs) and Junction Field Effect Transistors (JFETs) in a widely used commercial foundry SOI photonics technology lacking MOS devices but offering a variety of n- and p-type ion implants intended to provide waveguide modulators and photodetectors. Based on knowledge of device doping and geometry, simple compact LBJT and JFET device models for circuit simulation were developed. These models were then used to design basic transimpedance amplifiers integrated with optical waveguides, which were fabricated along with a suite of test devices. Experimental test results for the completed structures are reported and used to refine the compact device models. The second approach has been to show how low-loss optical waveguides can be integrated in a simple fully-depleted SOI CMOS technology used for in-house student project fabrication in the Carleton University Microfabrication Facility. In particular experimental and theoretical results are given for loss and photoresponse for Schottky diode photodetectors integrated with these waveguides. A CMOS transimpedance amplifier is also demonstrated in this technology.