If you want to determine your laser output, you can measure it by using a laser power meter. There are two types of laser power meters available – both are fairly pricey. One is a digital meter, which has proven to be reliable for multiple readings (and the most expensive). The other is a heat sink type, which looks like an aluminum block with a special thermometer in it. Both will work, but I recommend the digital one because it is what most laser system and tube manufacturers use.
—Coherent