Calculate laser pulse energy from power and repetition rate, or derive peak power, duty cycle, fluence, intensity, and photons per pulse.

Average power and pulse repetition rate, not optical frequency. Optional characteristics assume rectangular pulses and a uniform circular beam. This does not assess laser exposure safety.


Related Calculators

Laser Pulse Energy Formula

The following equation is used to calculate the Laser Pulse Energy. 

PE = LP / f

Variables:

  • Where PE is the Laser Pulse Energy (joules)
  • LP is average laser power (watts), excluding any continuous-wave background 
  • f is the pulse repetition rate (Hz), not optical carrier frequency 

To calculate mean laser pulse energy, divide average power by pulse repetition rate. Pulse characteristics use a rectangular temporal pulse and uniform circular beam: peak power = energy/duration, duty cycle = duration × rate, and fluence = energy/area. These assumptions do not apply directly to Gaussian pulse widths or Gaussian beam diameters. Photon count assumes one wavelength. The results do not assess laser exposure safety.

How to Calculate Laser Pulse Energy?

The following two example problems outline the steps and information needed in order to calculate the Laser Pulse Energy.

Example Problem #1:

  1. First, determine the laser power (watts). In this example, the laser power (watts) is measured to be 57.
  2. Next, determine the frequency of the laser (Hz). For this problem, the frequency of the laser (Hz) is calculated to be 42.
  3. Finally, calculate the Laser Pulse Energy using the formula above: 

PE = LP / f

Inserting the values from above and solving the equation with the imputed values gives: 

PE = 57 / 42 = 1.357 (joules)


Example Problem #2: 

Using the same process as example problem 1, we first define the needed variables outlined by the formula. In this case, the values are provided as: 

laser power (watts) = 95

frequency of the laser (Hz) = 4

Entering these values into the formula or calculator above gives us: 

PE = 95 / 4 = 23.75 (joules)