HALO Takes Runner-Up in OPN Photo Contest

The High Amplification Laser pressure Optic (HALO) was developed by NIST to measure kilo-watts of laser power with best-in-class accuracy. Here, optical power is determined by measuring the force a laser beam exerts when it is reflected by the HALO’s central mirror. Thirteen smaller mirrors redirect the beam towards the central mirror, multiplying the force and reducing the measurement uncertainty. This image was captured with a green HeNe laser, traced out with a white card to show the beam path.