A time-of-flight laser receiver for moving objects

The design of a time-of-flight laser receiver used for measuring and analyzing the motion of moving objects is presented. The receiver detects a small fraction of the light pulse reflected back from the 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 in 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.