Recently, a team of the National Institute of Standards and Technology (NIST) developed a high-precision point-access laser power meter. Its main working component is a folding mirror called a smart mirror. The use of this component makes it possible to measure laser power in real time in situ.
The researchers used a capacitive-based force sensor while combining high-reflectivity mirror and sensing elements into a compact, small-cube package—an embeddable laser optical system or laser pointer soldering system with a side length of 4 cm. Cube.
The smart mirror is compact and fast, allowing laser power to be reported at any time during the laser manufacturing process without interrupting the machining process. This smart mirror acts like a power meter that relates the effect of the laser on the mirror to the power of the laser (ie, brightness).
The smart mirror laser pointer power meter works by measuring the radiation pressure of the laser. The researchers used a capacitive compact capacitive force sensor to calculate the radiation pressure, plus a silicon spring that supported a circular plate with a high reflectivity mirror on one side and an electrode on the other. The other spring with the electrode is placed close to the first spring so that the two electrodes face each other to form a variable capacitor.
Researcher Alexandra B. Artusio-Glimpse said: “The manufacturer can continuously measure the laser power during each welding process and monitor the laser calibration in real time. As long as the laser has a problem, the technician can know in time through monitoring that there is no risk of wasting metal parts when welding is poor. ""
He also said: "Measurement of laser pointer power by measuring the pressure of the laser beam impacting the mirror is a very unique technology. So far, it is the only true in-situ laser power measurement technology, and other optical power measurement techniques. The biggest difference is that our approach allows us to continue working with the laser while measuring."