The piezoelectric aluminum nitride (AlN) was deposited by Plasma-Therm LLC. The magnetic-free linear optical isolator devices were fabricated at the Birck Center and the EPFL Center of MicroNanoTechnology. ISO (International Organization for Standardization) Class-6 nanofabrication cleanroom, where researchers from six Purdue academic colleges work at the forefront of photonics, nanoelectronics, energy, nanobiological technology, micro-electromechanical systems and nanomanufacturing. The Birck Center includes a 25,000-sq.-ft. “This is the first demonstration of a magnetic-free, electrically driven linear optical isolator on-a-chip, using Complementary Metal-Oxide Semiconductor (CMOS)-compatible fabrication technology and silicon-nitride (Si 3N 4) photonic integrated circuits (PICs),” says Bhave, who is also associate director of operations at the Birck Nanotechnology Center at Purdue. This non-reciprocal transmission property enables us to create electrically driven linear optical isolators.” Tian adds, “The strong mode coupling creates Rabi mode splitting and a transparency window in the forward direction whereas, in the backward direction, it remains as a single resonance and absorbs the input light. “This design creates an effective rotating acoustic wave, which allows indirect interband transition in only one direction among a pair of strongly coupled optical modes.” Hao Tian explains, who is one of the first authors. By driving three piezoelectric micromechanical system (piezoMEMS)-actuated acousto-optic modulators, they mimic the Faraday effect using a technique known as spatiotemporal modulation, eliminating the need for an external bias magnet. Piezoelectric refers to the ability of certain materials to generate an electric charge in response to applied mechanical stress, and vice versa. This breakthrough innovation was detailed in a paper, Magnetic-Free Silicon Nitride Integrated Optical Isolator, published on October 21 in Nature Photonics. “However, the magnetic materials are not compatible with current semiconductor foundry processes-crucial for commercial manufacture at scale-and electrically driven optical isolators are highly desired,” Bhave says.īhave’s research group, and another team from the École Polytechnique Fédérale de Lausanne (EPFL)-headed by Tobias Kippenberg, professor of physics and head of laboratory photonics and quantum measurement at the Swiss technical university-have replaced the magnetic materials with a piezoelectric thin film for an all-electrically-driven solution. In traditional optics, magnetic materials and external bias magnetic fields are used to achieve this optical isolation through the magneto-optical phenomenon known as the Faraday effect, discovered by English scientist Michael Faraday in 1845. Each isolator is only 200um diameter ring.īut the integration of on-chip optical gain elements-crucial to the laser’s ability to increase optical power-requires increased optical isolation, to protect the lasers from on-chip reflections, where the light can be reflected back onto the optical source and damage the equipment.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |