A Hybrid Analog-Digital Control System for Precision Laser Diode Current and Temperature Management

Abstract

This study presents the design, development, and performance evaluation of a hybrid analog-digital control system for achieving precision regulation of laser diode current and temperature. The proposed system integrates the fast real-time response of analog circuitry with the adaptive and programmable control features of a digital PID algorithm, ensuring high accuracy and stability under varying operational conditions. The analog subsystem manages rapid signal fluctuations and provides noise suppression, while the digital controller performs dynamic tuning, calibration, and temperature compensation. Experimental analysis revealed that the hybrid system achieved a steady-state current error of ±0.02 A and a temperature deviation of ±0.05°C, outperforming conventional analog and digital systems in terms of response time, overshoot, and stability. The system maintained a highly stable optical output of 5.00 ± 0.01 mW, even under fluctuating ambient temperatures between 20°C and 40°C. Comparative results confirmed improvements in linearity (R² = 0.995), efficiency (95.8%), and signal integrity (noise reduced to 3.1 mV RMS). These findings demonstrate that the hybrid architecture effectively bridges the limitations of standalone control systems, providing superior dynamic performance, energy efficiency, and long-term operational reliability. The proposed hybrid control framework offers a robust, scalable solution for precision laser driver applications in photonics, optical communication, and scientific instrumentation.