Laser-Engineered Technique Enables Optical Switching in Thicker Magnetic Layers

Engineers at UC San Diego have overcome previous limitations in optical switching by using specially shaped laser beams to manipulate magnetic information in thicker material stacks without requiring external magnetic fields. The technique successfully operated on nine alternating layers of platinum and cobalt—far exceeding the three-layer threshold that previously suppressed switching capability. This advancement could enable data storage systems that are over 1,000 times faster and more compact than current magnetic field-based approaches.

Scientists have long sought ways to encode and retrieve digital information more efficiently. Magnetic storage relies on reversing tiny magnetized regions, but traditional methods using external magnetic fields are energy-intensive and slow. Light-based approaches offer theoretical advantages due to their ability to deliver concentrated energy in extremely brief pulses, potentially accelerating data writing speeds dramatically while reducing power consumption.

A key barrier had prevented researchers from applying optical switching to sufficiently thick material layers. The UC San Diego team addressed this by precisely shaping their laser beam rather than modifying the magnetic materials themselves. This alternative engineering strategy eliminated previous constraints, allowing the technique to function across nine layers instead of just three, while also removing the need for specifically polarized light during operation.