This paper introduces the principles of pulse chopping with fast-response electrooptic deflectors. Laser pulses with a wide range of desirable pulse-width can be obtainedeasily using this method. Dependence of pulse-width upon light beam focus spot, size ofchopping hole and scan velocity is discussed theoretically.Chopped from a Q- switch singlelongitudinal mode pulse with 20 ns pulse-width by using a φ0. 36 chopping hole, a short lightPulse with a pulse-width 280 ps and rise-edge 140 ps is realized experimentally.