A time-of-flight laser receiver for moving objects

The design of a time-of-flight laser receiver for measuring and analyzing the motion of moving objects is presented. The receiver detects a small fraction of the light reflected back from an object and forms an ECL-level pulse for measuring the light pulse´s time of flight. The timing errors caused by amplitude variations of the reflected light pulses are minimized by utilizing the special characteristics of the application. Measured timing errors are within ±7 ps over a dynamic range of amplitude variations of more than 1:10. The bandwidth of the preamplifier of the receiver is about 200 MHz and the input noise current density about 3 pA/√Hz.