摘要
Lithium niobate^(1,2) is a ferroelectric crystal that features superior electrooptical,nonlinear optical,and acoustic optical performance,and it is thus prominent in various optoelectronic applications.Recent breakthroughs in the fabrication of thin film lithium niobate(TFLN)combine the unique features of the bulk crystal onto an integrated platform with submicron light confinement,driving new records in reducing the energy consumption for high-speed electro-optical modulation,3–5 the footprint for acoustic wave filtering,6 and the power requirement for efficient optical frequency conversion.7–9 TFLN is mainly fabricated using the smart cut technique,10,11 which was developed for silicon-oninsulator materials12 and is known for its capability for manufacturing high-quality,large-sized crystalline wafer.Revolutionary performances are expected by moving from bulk to TFLN,e.g.,in the form of lithium-niobate-on-insulator(LNOI)optical communication and wireless communication devices,and this trend may also lead to fundamental breakthroughs in optical computation,microwave photonics,and quantum optics,as discussed below.
