An optical analog of the electronic sampling oscilloscope is proposed, and preliminary experimental results are presented. The sampling pulses, ∼4 psec in duration, are produced by a mode‐locked Nd:glass laser. They are mixed in a KDP crystal with pulses of ∼800‐psec duration, from a mode locked He☒Ne laser. The optical sum frequency is detected and displayed on a conventional oscilloscope. The pulse separations in the two lasers differ in such a way that, as time goes by, the sampling pulse scans the He☒Ne pulse. There results, on the conventional oscilloscope, a sampled display of the He☒Ne pulse.