Analysis of the effect of modulation parameters on optical power from the indirect time of flight LiDAR

Intensity modulation plays a crucial role in developing the indirect Time of Flight (i-ToF) LiDAR because it enables the system to precisely measure distances, enhance accuracy and resolution, reduce noise, and avoid environmental interference. This work observes the modulation parameters—such as bias current on the laser diode, modulation frequency, and amplitude of modulation—that impact LiDAR’s performance. By combining such parameters, the average optical power transmitted by the LiDAR system is investigated by an optical power meter at a distance of up to 55 meters. The results demonstrate that changing the bias current increases the average optical power from 14.14 mW at 60 mA, 29.53 mW at 100 mA, and 40.6 mW at 130 mA. However, adjusting modulation frequencies of 2 MHz and 10 MHz and the modulation amplitudes of 1000 mV and 1500 mV had minimal influence on the average optical power. The optimal combination of 60 mA bias current, 2 MHz modulation frequency, and 1500 mV amplitude modulation results in stable optical power, high accuracy, and operational safety for i-ToF LiDAR. This analysis recommends that a combination of modulation parameters should be compromised between increasing optical power to achieve a good signal-to-noise ratio (SNR) and safe operation.