Putting Lasers on a Scale
Scales are a common instrument in many places, including laboratories, stores, and our bathrooms because it is useful to weigh something there and in other places. Now scales may be getting another use, thanks to researchers at NIST who have found a way to measure a laser's output.
To measure a laser's output, for calibration purposes, typically requires aiming it at a special detector that heats up due to the intense light. This change in temperature causes a change in electrical conductance, which is then measured to determine the power of the laser. While this method can be very accurate, it is not very efficient and is not always viable with the most powerful lasers, designed to cut through objects. The new NIST method however measures the force a laser applies to a mirror with a scale, which is a much simpler process. Also, because a standard mass can be used to calibrate the scale, it does not require the scale be periodically evaluated.
Eventually we may see the equipment for this technique costing a fifth as much as the traditional setup, while also producing accurate results in a tenth the time. Another benefit to this approach is that it does not have to interrupt the laser's use, as the mirror could just aim the light at its intended target.