Sensitivity issues in photonic sensor system design

Issues involving the sensitivity of a photonic modulator without preamplifier are discussed in the areas of modulator type, sensor system type, and the benefit of high laser power. It is noted that photonic sensor system small signal sensitivity is approaching that of the nonphotonic sensor. To make them more sensitive and more practical, continued progress in increasing the figure of merit is needed. Making the electrooptic coefficient r larger in man-made modulator structures is akin to obtaining more noise-free gain at the system front end; it can reduce the required laser power. If the more complex sensor structures are used, chip-based phase and frequency controllers will be needed.<>