5. Laser power/energy measurement

As their name suggests, thermopiles operate on the basis of heat flow, with a variation in temperature on the sensing surface being translated into a power reading. Pyroelectrics also react to the heat generated by a laser pulse, but operate in a very different way. Pyroelectrics are basically made up of a crystal containing permanent dipoles, whose thermal response is very rapid. Unlike thermopiles, which heat up slowly and give an accurate measurement once their temperature has stabilized, a pyroelectric crystal...