Integrated optical E-field sensor based on balanced Mach-Zehnder interferometer

We report here a balanced Mach-Zehnder interferometer-based integrated optical E-field sensors (MZI IOES) configuration, where the output Y-branch is replaced by a 2x2 directional coupler. Based on detailed theoretical and experimental investigations, we prove such IOES configuration has a simple linear transfer function, as well as much improved optical bias control, highly desirable for practical field applications. The optical biases of the fabricated devices deviate from the ideal bias by 3.3 degrees, 7.9 degrees, and 14.5 degrees, respectively. The theoretical analysis and experiment results show that this type of sensor inherits the advantages of a conventional MZI sensor and directional coupler sensor: with a sinusoidal transfer function and a better optical bias. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3651809]