Traditionally, when someone wished to measure the total power delivered by a laser beam, they had to use something called a ball calorimeter. As the laser heated the interior of the ball, temperature readings would be taken. Now, however, a system has been created that utilizes reusable glass boards. It can measure a laser's total energy along with the total power and power density anywhere inside the beam more than one hundred times per second. It should be a boon to developers of high-energy laser weapons, as it will reduce the time required for testing, and get the weapons in the field faster.
Read the full article: Glass-based system developed for testing laser weapons