Japanese researchers achieve breakthrough in magneto-optical technology

Researchers at Tohoku University in Sendai, Japan, and Toyohashi University of Technology in the Japanese town of the same name have developed a new method to produce transparent magnetic materials through laser heating. This is a major advance in optical technology and represents a new approach to integrating magneto-optical materials into optical devices. This opens a wide, but so far challenging, field of applications.

“The key to this breakthrough lies in the production of cerium-substituted yttrium iron garnet (Ce:YIG), a transparent magnetic material, using a special laser heating technique,” ​​explains Professor Taishi Goto, lead author of a recently published research paper. Optical materials Published study. “This method solves the key challenge of integrating magneto-optical materials into optical circuits without damaging them – a problem that has hampered progress in miniaturizing optical communications devices.”

Magneto-optical isolators are needed for stable optical communication and act as controls that can move optical signals in one direction but not the other. This makes clear communication possible.

Because this integration can only be performed using high-temperature processes, solving the problem has long been considered a challenge. Goto and his colleagues overcame this challenge by using so-called laser annealing.

This is a technique in which specific areas of the material are heated very selectively using a laser. This allows precise control as only specific areas are heated without affecting the surrounding areas.

In order to avoid chemical processes that occur with the surrounding air when working with corresponding materials, the team developed a new device that heats materials in a vacuum using a laser. This should allow precise heating of the smallest areas of around 60 micrometers without altering the surrounding materials.

Goto and his team expect that “the transparent magnetic material produced using this method will significantly improve the development of compact magneto-optical insulators, which are essential for stable optical communication.” The new process also opens “opportunities to develop powerful miniature lasers, high-resolution displays and small optical devices,” the professor said.