Barium titanate controls the speed of light with electrical voltage. This has long attracted optical chip developers, but growing an atomically smooth film on silicon proved elusive — the process resembled trying to do a puzzle during an earthquake. A new method tames the chaos: molecules self-assemble into flawless order, like magnetic pieces snapping only into their designated spots. On a 100-millimeter wafer, a film formed with layers so flat that every atom is visible. Voltage sensitivity hit a record 248 pm/V. In other words, a battery's worth of voltage can steer light more powerfully than an optical lens.
This brings us closer to an era of affordable photonic circuits for instant optical measurements and spectrometers in medicine.
Barium titanate, discovered in the 1940s, throws a spark when struck. This same crystal hides inside cheap lighters, striking fire every day.
In Gibson's Neuromancer, computers communicate with light. With films like these, optical chips leap from science fiction into server racks.