Laser-crystal sensor measures strong magnetic fields in challenging environments

[Marlin]

Laser-crystal sensor measures strong magnetic fields in challenging environments

https://www.ans.org/news/2026-07-21/article-8231/lasercrystal-sensor-measures-strong-magnetic-fields-in-challenging-environments/

[Core Content]

Sandia National Laboratories patented a magneto-optical sensor using rare earth crystals to measure intense magnetic fields and electrical currents. The device utilizes polarized laser light to detect field strength without requiring external calibration. This technology offers increased resilience to radiation and electromagnetic interference, providing a potential alternative for monitoring fusion plasma environments where conventional metallic sensors often fail.

Researchers at Sandia National Laboratories have patented a magneto-optical sensor, which uses a rare earth crystal and laser light to measure the strength of intense magnetic fields and electrical currents.

"We think this technology is a pretty major improvement in measuring magnetic fields," said Israel Owens, a Sandia physicist and co-inventor of the sensor. "We think it'll be essential especially for research in fusion, high-energy physics, and the power utilities industry. We're really excited about where things are going."

How it works: In the sensor, polarized laser light shines through a crystal around the size of a pencil eraser. When the crystal is exposed to a magnetic field, the polarization of the light rotates in a way that is linearly proportional to the strength of the part of the magnetic field that is parallel to the long side of the crystal. By precisely measuring that rotation, the system can determine the strength of the magnetic field, Owens said.

Read the full article at ans.org:
https://www.ans.org/news/2026-07-21/article-8231/lasercrystal-sensor-measures-strong-magnetic-fields-in-challenging-environments/