LED Device Characterization with a Harmonic Balance Approach

A simplified mathematical model is derived to describe the complex nature of frequency-dependent second-order nonlinearities in directly modulated LEDs. The harmonic balance method is used based on a well-accepted carrier density rate equation. The results are in excellent agreement with both numerical simulations and laboratory experiments with commercially available LEDs. One possible application of such an analytical model is the time efficient evaluation of pre-distortion or power loading techniques to minimize nonlinear signal distortions in LED-based communication systems.