Advanced sensor systems such as those found in the next generation of aircraft, automated factories, process control systems and mobile platforms will require many sensing points. Dielectric optical sensors and data paths provide the ideal medium for measurement and transmission of status and command information. Optical sensors are lightweight, highly reliable, impervious to all forms of electromagnetic interference and, in some cases, low cost. This paper reviews optical sensors and divides the sensor types into eleven optical sensing principles. Each optical sensing principle is analyzed as to its ability to be used efficiently and cost effectively in an optical sensor network. Analysis shows that the reflection sensor, referenced at two wavelengths and spatially multiplexed, is a strong candidate for industrial optical sensor buses.