Hojoong Jung
National Institute of Standards and Technology(NIST), USA
地点：唐仲英楼A213
时间：2018-12-21 10:00
Despite the outstanding studies on silicon nitride (SiN) as a nonlinear material, the high stress of low-loss SiN (~1GPa) have been a bottleneck in fabrication and applications. Here we introduce low stress, low loss, and high n2 integrated tantalum pentoxide (Ta2O5) devices for Kerr nonlinear photonics. More than 800 nm-thick Ta2O5 is very uniformly ( 3×106) microring resonator is obtained based on optimized deposition, annealing and fabrication techniques. Optical parametric oscillation threshold powers as low as 10 mW are measured, and based on the threshold powers, the nonlinear refractive index of Ta2O5 at telecommunication wavelengths is estimated as n2 = 6.2 ± 2.3 ×10-19 m2/W, which is about three times higher than the widely used nonlinear material, SiN. Relatively low thermo-optic coefficient of 8.8 × 10-6 /K is also measured while heating the chip using the thermoelectric cooler (TEC). From these Ta2O5 microring resonators, we observe Kerr soliton combs and 1.6 octave spanning supercontinuum generation.
Hojoong Jung received his B.S.in Physics and M.S. in Applied Physics from Yonsei University, South Korea in 2008 and 2010, and his PhD in Electrical Engineering from Yale University, in 2017.5. He finished his Research Associate work at Yale University from 2017.6 to 2017.8. He is now an Research Associate in National Institute of Standards and Technology (NIST), USA. His research qualifications are: 8 years of experience in silicon nanophotonics. Nonlinear optical devices design, simulation with COMSOL, fabrication with E-beam lithography and characterization with high power laser.2 years of experience in fiber optics, including fiber drawing tower installation and fiber fabrication.