Automatic bias control of Mach-Zehnder modulator using RMSProp-based gradient feedback optimization
摘要
The proposed automatic bias control technique for Mach-Zehnder modulators (MZMs) utilizes Root Mean Square Propagation (RMSProp) and optical feedback to adjust the DC bias voltage based on the gradient of the MZM’s transfer function. This approach maximizes the signal-to-noise ratio (SNR) without the need for RF dither signals, relying instead on optical output power measurements and numerical gradient estimation. Bias drift, primarily caused by environmental variations such as temperature changes and mechanical disturbances, severely affects modulation stability in high-speed optical communication systems. To validate its effectiveness, the proposed method was experimentally evaluated. In experiments conducted over 30 h, the proposed method maintained the bias voltage within