Measuring optical power and energy depends on an understanding of the types of sensors and instruments available, and on requirements such as wavelength response, dynamic range, damage threshold, and maximum repetition rate.
Power and energy meters measure the output of an optical source. They are a necessity in a wide variety of applications in the lab, on the production floor, or in the field, whether the emission is from low-light sources, such as fluorescence, or from high-energy pulsed lasers.
No doubt that the need to accurately measure laser power and energy has increased as more of these systems are used in medical procedures and industrial processes.
Although a fairly simple process, this measurement is not as straightforward as an electric power measurement.
With lasers, more attention must be paid to the selection of the right sensor as different sensors perform different measurements.
Selecting the wrong sensor can result in inability to measure well or can even destroy the sensor.