The response of a Class B laser to a rapid change in one of its parameters is known to be accompanied by delay and ringing. It has been theoretically and numerically shown that the transition can be modified by using adequate functional shapes for the control parameter (e.g., the laser pump) in order to steer the laser from one point of operation to another. Here we experimentally show the implementation of these ideas in a commercial device: a semiconductor laser. We establish a procedure for optimizing a controlled switch-on and switch-off and obtain a clean, fast, and reliable square pulse, either in a single shot or in a repetitive sequence. The generality of this procedure promises a wide field of application for a variety of laser systems.