The field of nonlinear photonics is in full development. This special issue of Photonics Research takes you through the current issues of this fast-growing field of research, drawing on the current state of the art an...The field of nonlinear photonics is in full development. This special issue of Photonics Research takes you through the current issues of this fast-growing field of research, drawing on the current state of the art and seeking, through a selection of articles, to outline some trends for the future.展开更多
Submicron-thick thin-film lithium niobate(TFLN)has emerged as a promising platform for nonlinear integrated photonics.In this work,we demonstrate the efficient simultaneous generation of broadband 2nd–8th harmonics i...Submicron-thick thin-film lithium niobate(TFLN)has emerged as a promising platform for nonlinear integrated photonics.In this work,we demonstrate the efficient simultaneous generation of broadband 2nd–8th harmonics in chirped periodically poled(CPP)TFLN.This is achieved through the synergistic effects of cascadedχ^((2))nonlinear up-conversion andχ^((3))self-phase modulation,driven by near-infrared femtosecond pulses with a central wavelength of 2100 nm and a pulse energy of 1.2μJ.Remarkably,the 7th and 8th harmonics extend into the deep ultraviolet(DUV)region,reaching wavelengths as short as 250 nm.The 3rd–8th harmonic spectra seamlessly connect,forming a broadband supercontinuum spanning from the DUV to the visible range(250–800 nm,-25 d B),with an on-chip conversion efficiency of 19%(0.23μJ).This achievement is attributed to the CPP-TFLN providing multiple broadband reciprocal lattice vector bands,enabling quasi-phase matching for a series ofχ^((2))nonlinear processes,including second harmonic generation(SHG),cascaded SHG,and third harmonic generation.Furthermore,we demonstrated the significant role of cascadedχ^((2))phase-mismatched nonlinear processes in high-harmonic generation(HHG).Our work unveils the intricate and diverse nonlinear optical interactions in TFLN,offering a clear path toward efficient on-chip HHG and compact coherent white-light sources extending into the DUV.展开更多
文摘The field of nonlinear photonics is in full development. This special issue of Photonics Research takes you through the current issues of this fast-growing field of research, drawing on the current state of the art and seeking, through a selection of articles, to outline some trends for the future.
基金National Natural Science Foundation of China(12434016,11974119)Science and Technology Project of Guangdong(2020B010190001)National Funded Postdoctoral Researcher Program(GZB20240785)。
文摘Submicron-thick thin-film lithium niobate(TFLN)has emerged as a promising platform for nonlinear integrated photonics.In this work,we demonstrate the efficient simultaneous generation of broadband 2nd–8th harmonics in chirped periodically poled(CPP)TFLN.This is achieved through the synergistic effects of cascadedχ^((2))nonlinear up-conversion andχ^((3))self-phase modulation,driven by near-infrared femtosecond pulses with a central wavelength of 2100 nm and a pulse energy of 1.2μJ.Remarkably,the 7th and 8th harmonics extend into the deep ultraviolet(DUV)region,reaching wavelengths as short as 250 nm.The 3rd–8th harmonic spectra seamlessly connect,forming a broadband supercontinuum spanning from the DUV to the visible range(250–800 nm,-25 d B),with an on-chip conversion efficiency of 19%(0.23μJ).This achievement is attributed to the CPP-TFLN providing multiple broadband reciprocal lattice vector bands,enabling quasi-phase matching for a series ofχ^((2))nonlinear processes,including second harmonic generation(SHG),cascaded SHG,and third harmonic generation.Furthermore,we demonstrated the significant role of cascadedχ^((2))phase-mismatched nonlinear processes in high-harmonic generation(HHG).Our work unveils the intricate and diverse nonlinear optical interactions in TFLN,offering a clear path toward efficient on-chip HHG and compact coherent white-light sources extending into the DUV.
