The planned goal of the project is to create a battery powered, ditherless bias controller to encode radio data into the optical domain using a Mach-Zehnder Modulator (MZM). Using two photodiodes and an MCU, the bias of the MZM will be appropriately adjusted to minimize signal drift. The second core goal is to construct an optical tap system that monitor the power of the system before and after the light passes through the MZM. To properly encode data into the optical domain, the system must be isolated from electrical noise. Similarly, the signal must have a high SNR, reducing error when transmitting optical data through fiber. To create an effective optical tap the system must accurately split the laser signal between multiple couplers and send current readings from photodiodes to the MCU. As the system must be readily integrated into other military systems, the entire project must be lightweight and small spatially. Finally, to reduce optical noise, each subsystem is interfaced using fiber. To achieve these goals and objectives, a CW laser outputting 50mW of 1550nm light is used. This light is then transmitted through a polarization-maintaining fiber splitter, with a portion being sent into a photodiode, tapping off a portion for monitoring of the input signal. The remaining signal is then sent through the MZM, where the radio data is encoded into the optical domain and then sent to a final photodiode. Such a system can be used for military applications. Transmitting data in the optical domain can increase the security of a communication channel secure network, reducing the potential for malicious tampering or tapping of signal. Our system is of particular interest due to its relative simplicity and significantly smaller form factor than other
commercial units.
Advisors: Dr. Samuel Richie, Dr. Lei Wei, and Dr. Aravinda Kar
Sponsor: Critical Frequency Design