Lithium Niobate on Insulator (LNOI) is a new material for integrated photonics that employs Lithium Niobate as a thin-film deposited on a silica layer.
While bulk Lithium Niobate (LN) is a standard for optical phase modulators, its thin-film form promises outstanding performance, besting other integrated modulator technologies. In this form LN can be patterned to obtain photonic integrated circuits (PIC) in a way similar to Silicon Photonics on SOI.
The fabrication of integrated waveguides in LNOI is a first step that opens many opportunities for the production of PICs featuring fast optical phase modulators with extremely low insertion losses and very high signal fidelity, crucial parameters for many sensing and datacom applications.
INPHOTEC Foundation demonstrated for the first time in Italy a LNOI PIC featuring low-loss LNOI waveguides, thanks to a collaboration with the PNTLab at CNIT, which supported the modeling and design of the building blocks on the new platform.
The fabrication of low loss LNOI waveguides requires developing dedicated lithography and etching processes since LN has totally different chemical properties with respect to silicon-based materials.
The first prototype of single-mode waveguides, a “nano-structure” with a width of only 700 nm, displayed optical propagation losses of approximately 3.5 dB/cm, in line with current Silicon Photonics waveguides, and the engineers at INPHOTEC and CNIT think that the state of the art of 0.5 dB/cm will be reached soon.
The activity related to the inertial sensors capabilities was funded by the Italian company CIVITANAVI SYSTEMS S.R.L.. This is an important milestone for the development of new integrated optical circuits in Italy. This technology is expected to be mature enough in two years to offer multi-project LNOI fabrication runs.
INPHOTEC may then become one of the first technology centers in Europe to provide multi-project LNOI fabrication services to academic customers.