An international research team has developed a device that can direct, switch and store thermal radiation without ongoing power. The breakthrough separates heat absorption from emission, overcoming a long-standing materials science limit known as reciprocity.
Led by Professor Koichi Okamoto and Dr. Shunsuke Murai at Osaka Metropolitan University, the group combined magneto-optical materials with a phase-change substance called GST. The resulting metagrating responds to magnetic fields and light direction, allowing heat to be steered at near-normal incidence.
The device switches reliably between states and retains its configuration after power is removed. Earlier designs needed steep light angles and lost memory once power was cut.
Dr. Murai said the work makes heat radiation behave in a smarter way. Professor Okamoto added that the goal is compact devices that manage heat as precisely as circuits manage electricity, with uses in sensors, energy systems and photonic memory.
The findings appear in the journal Laser.