Pulsed lasers

When people think of lasers they generally perceive a continuous beam of light fired into the distance. This kind of laser we call 'continuous wave mode'. However increasingly lasers operate in a pulsed mode, which means they switch on and off very quickly.

Pulsed lasers have greater peak power

One reason to pulse a laser beam is that in an almost instantaneous burst of laser light we can ensure far more 'peak' power than is possible in a continuous wave. When we measure 'peak' power we are only measuring the energy that is delivered during that fraction of a second when the laser is emitted whereas when we are measuring average power we have to measure the time between pulses which will be much longer in comparison (seconds rather than fractions of a second). So although the average power in a continuous laser beam is higher than in a pulsed laser the peak power in a laser pulse is much higher.

Did you know?

The current record for the shortest laser pulse is just under 4 femtoseconds, or 0.000000000000004 of a single second.