New Zen-like laser produces pico-second bursts of ... nothing.

In an advance that sounds almost Zen, researchers at the National Institute of Standards and Technology and JILA, a joint institute of NIST and the University of Colorado at Boulder, have demonstrated a new type of pulsed laser that excels at not producing light. The new device generates sustained streams of "dark pulses" -- repeated dips in light intensity -- which is the opposite of the bright bursts in a typical pulsed laser.
("stand back, or I shall fire 60 trillionths of second of darkness at you...")