[OPTICAL REVIEW Vol. 6, No. 5 (1999) 464-470]
Geometrical Form Factor Improvement for Receiving System of Infrared Lidar
Kouki IKUTA, Tsutomu KUDO, Noboru YOSHIKANE, Nilesh J. VASA, Yuji OKI and Mitsuo MAEDA
Department of Electronic Device Engineering, Graduate School of Information Science and Electrical Engineering, Kyushu University, 6-10-1, Hakozaki, Fukuoka, 812-8581 Japan
(Received March 8, 1999; Accepted June 26, 1999)
Improvement of an infrared light detection and ranging (IR-lidar) system for a short range (0-1000 m) and with high resolution is studied to enhance a geometrical form factor. Theoretical modeling of Mie scattering echo signals agrees with the experimental results. Introduction of a lens in front of the detector is effective for increasing the geometrical form factor, and a significant improvement in the received signal intensity is achieved, especially for short-range measurements around 100 m. This is useful for the IR-lidar system with a detector diameter of less than 1 mm. In the theoretical model, a ray-tracing technique was applied and a transmitting laser beam with Gaussian profile was considered for better accuracy.
Key words : lidar, laser radar, ray tracing, light detection system, Mie scattering, geometrical form factor, short-range detection