Optical sensing, and the integration of sensors and electronics into Sensor on a Chip and Sensor on a Package systems are an approach to the creation of miniaturized, portable, customizable, low cost sensor systems for rapid health diagnostics, medical research, environmental monitoring, and security monitoring. To integrate optical sensing systems that are autonomous, it is essential to integrate the sensor, light source, and light detection into a single substrate or chip. The integration of this optical system with signal control and processing electronics enable discrimination with individually customized sensors in sensor arrays, and high sensitivity levels. Thin film optoelectronic active device integration with planar optical passive devices is a heterogeneous integration method for fabricating planar lightwave integrated circuits at the chip level and planar lightwave integrated systems at the substrate and package level.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.