Power
The rate of energy delivery. Power (or more correctly, radiant flux) is used to express the output of continuous (CW) lasers and is measured in Watts (W). One Watt is a Joule per second. The average power from a pulsed laser is the product of energy per pulse (in Joules) and pulse repetition frequency (in Hertz). For example, if a giant pulsed laser produces 10 pulses per second (i.e. 10Hz) and the energy of each pulse is 100mJ (1 x 10-1 J), the average power is 10 * 1 x 10-1 equals 1 Watt.