Study on the time of flight optical ranging by using direct modulation of the laser diode

• Main Authors: Hanto, Dwi, Sartika, Rofianingrum, Mefina Yulias, Widiyatmoko, Bambang
• Format: Conference Proceeding
• Language: English
• Subjects: Amplitudes; Function generators; Lasers; Modulation; Optical communication; Photometers; Reference signals; Remote sensing; Semiconductor lasers
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0108831

Optical ranging is now an interested method that has been implemented in various purposes such as lidar, remote sensing, communication, and metrology. In our paper, we investigate the effect on the direct modulation signal of laser diode that is applied on time of flight (ToF) optical ranging. Our main system comprises a laser diode, a function generator, and a photodetector. The intensity of laser diode is sinusoidally modulated by varying injected current produced by a function generator. In order to evaluate a ranging measurement, a modulated optical signal is captured by using a photodetector and compared with a reference signal from function generator. To study the effect on the direct modulation of laser diode, we employ two types of laser diode with different wavelengths and optical power. Besides, varying amplitude and frequency of modulating signal are also performed to understand the characteristics of a modulated signal. Then, we implement our system in ranging applications by measuring a phase shift between a modulated signal and a reference signal. The results show that the amplitude and frequency of modulating signal, as well as the optical power of laser diode should be considered in order to achieve the desired performance in design laser optical ranging applications.