Optical fiber imaging laser radar

Abstract

We have developed the Optical Fiber Imaging Laser Radar based on the focal plane array detection using the small number of detectors less than the number of the focal plane array resolution. For this focal array detection, first, we made the optical fiber dissector which has one vertical cross section of the 35 x 35 optical fibers square array at one end to receive the reflected laser pulse from an object and 25 vertical cross sections of the 7 x 7 optical fibers array extracted from the 35 x 35 optical fibers square array at 25 other ends to guide the dissected laser pulse to the 25 InGaAs photodiode pulse detectors of the 25 channels of the parallel pulse counter. The 7 x 7 optical fibers arrays are the mode (5,5) residual classes from the 35 x 35 optical fibers square array. Second, we shaped the most of Erbium doped optical fiber laser pulse into the laser pulse with the beam of the elliptic cross section that falls into one 5 x 5 area of the vertical cross section of the 35 x 35 optical fibers square array when it is received. And we made a mask with a window of a size 5 x 5 optical fibers’ cross section to ensure no cross talk in the receiver of the Optical Fiber Imaging Laser Radar. Then, we controlled the direction of the shaped laser pulse to scan and reconstruct the received data from the 25 channels of the parallel pulse counter to the actual order data of the Imaging Laser Radar. The developed Imaging Laser Radar shows that the image resolution between the range image and the object is within one pixel difference and that the range resolution is under 15cm.