Integrated photonics provides unprecedented opportunities to pursue advanced nonlinear light sources with lowpower consumptions and small footprints in a scalable manner,such as microcombs,chip-scale optical parametri...Integrated photonics provides unprecedented opportunities to pursue advanced nonlinear light sources with lowpower consumptions and small footprints in a scalable manner,such as microcombs,chip-scale optical parametric oscillators and integrated quantum light sources.Among a variety of nonlinear optical processes,high-efficiency second harmonic generation(SHG)on-chip is particularly appealing and yet challenging.In this work,we present efficient SHG in highly engineerable semi-nonlinear waveguides consisting of electron-beam resist waveguides and thin-film silicon nitride(SiN)/lithium niobate(LN).By carefully designing octave-separating bound states in the continuum(BICs)for the nonlinear interacting waves in such a hybrid structure,we have simultaneously optimized the losses for both fundamental frequency(FF)and second harmonic(SH)waves and achieved modal phasing matching and maximized the nonlinear modal overlap between the FF and SH waves,which results in an experimental conversion efficiency up to 4.05%W^(-1)cm^(-2).Our work provides a versatile and fabrication-friendly platform to explore on-chip nonlinear optical processes with high effciency in the context of nanophotonics and quantum optics.展开更多
基金National Key R&D Program of China(2021YFA1400803)Guangdong Natural Science Funds for Distinguished Young Scholars(2022B1515020067)+2 种基金National Natural Science Foundation of China(11904424,11874437,62035017)Key-Area R&D Program of Guangdong Province(2018B030329001)The Fundamental Research Funds for the Central Universities,Sun Yat-sen University(221gqb32).
文摘Integrated photonics provides unprecedented opportunities to pursue advanced nonlinear light sources with lowpower consumptions and small footprints in a scalable manner,such as microcombs,chip-scale optical parametric oscillators and integrated quantum light sources.Among a variety of nonlinear optical processes,high-efficiency second harmonic generation(SHG)on-chip is particularly appealing and yet challenging.In this work,we present efficient SHG in highly engineerable semi-nonlinear waveguides consisting of electron-beam resist waveguides and thin-film silicon nitride(SiN)/lithium niobate(LN).By carefully designing octave-separating bound states in the continuum(BICs)for the nonlinear interacting waves in such a hybrid structure,we have simultaneously optimized the losses for both fundamental frequency(FF)and second harmonic(SH)waves and achieved modal phasing matching and maximized the nonlinear modal overlap between the FF and SH waves,which results in an experimental conversion efficiency up to 4.05%W^(-1)cm^(-2).Our work provides a versatile and fabrication-friendly platform to explore on-chip nonlinear optical processes with high effciency in the context of nanophotonics and quantum optics.
