Combining integrated photonics and MEMS technology, scientists from EPFL and Purdue University demonstrate monolithic piezoelectric control of integrated optical frequency combs with bulk acoustic waves. The technology opens up integrated ultrafast acousto-optic modulation for demanding applications.
Piezoelectric materials can convert electrical voltage to mechanical displacement and vice versa. They are ubiquitous in modern wireless communication networks such as in cellphones. Today, piezoelectric devices, including filters, transducers and oscillators, are used in billions of devices for wireless communications, global positioning, navigations, and space applications.
In an article published in Nature, a collaboration lead by Professor Tobias J. Kippenberg at EPFL and Professor Sunil A. Bhave at Purdue University has combined piezoelectric aluminium nitride (AlN) technology – used in modern cellphones’ radio frequency filters – with ultralow-loss silicon nitride (Si3N4) integrated photonics, demonstrating a new scheme for on-chip acousto-optic modulation.
The hybrid circuit allows wideband actuation on photonic waveguides with ultralow electrical power – a feat that has been so far challenging. The circuit itself was manufactured using CMOS-compatible foundry processes, which are widely used to construct microprocessors, microcontrollers, memory chips, and other digital logic circuits.
Source:”Shaking light with sound”, Junqiu Liu, Nik Papageorgiou, EPFL