Mode-locked microcombs with flat spectral profiles provide the high signal-to-noise ratio and are in high demand for wavelength division multiplexing(WDM)-based applications,particularly in future high-capacity commun...Mode-locked microcombs with flat spectral profiles provide the high signal-to-noise ratio and are in high demand for wavelength division multiplexing(WDM)-based applications,particularly in future high-capacity communication and parallel optical computing.Here,we present two solutions to generate local relatively flat spectral profiles.One microcavity with ultra-flat integrated dispersion is pumped to generate one relatively flat single soliton source spanning over 150 nm.Besides,one extraordinary soliton crystal with single vacancy demonstrates the local relatively flat microcomb lines when the inner soliton spacings are slightly irregular.Our work paves a new way for soliton-based applications owing to the relatively flat spectral characteristics.展开更多
The optical frequency comb based on microresonators(microcombs)is an integrated coherent light source and has the potential to promise a high-precision frequency standard;self-reference and a long-term stable microcom...The optical frequency comb based on microresonators(microcombs)is an integrated coherent light source and has the potential to promise a high-precision frequency standard;self-reference and a long-term stable microcomb are the keys to this realization.Here,we demonstrated a 0.7-octave spectrum Kerr comb via dispersion engineering in a thin-film lithium niobate microresonator,and the single-soliton state can be accessed passively with long-term stability over 3 h.With such a robust broadband coherent comb source using thin-film lithium niobate,a fully stabilized microcomb can be expected for massive practical applications.展开更多
Optical frequency combs,a revolutionary light source characterized by discrete and equally spaced frequencies,are usually regarded as a cornerstone for advanced frequency metrology,precision spectroscopy,high-speed co...Optical frequency combs,a revolutionary light source characterized by discrete and equally spaced frequencies,are usually regarded as a cornerstone for advanced frequency metrology,precision spectroscopy,high-speed communication,distance ranging,molecule detection,and many others.Due to the rapid development of micro/nanofabrication technology,breakthroughs in the quality factor of microresonators enable ultrahigh energy buildup inside cavities,which gives birth to microcavity-based frequency combs.In particular,the full coherent spectrum of the soliton microcomb(SMC)provides a route to low-noise ultrashort pulses with a repetition rate over two orders of magnitude higher than that of traditional mode-locking approaches.This enables lower power consumption and cost for a wide range of applications.This review summarizes recent achievements in SMCs,including the basic theory and physical model,as well as experimental techniques for single-soliton generation and various extraordinary soliton states(soliton crystals,Stokes solitons,breathers,molecules,cavity solitons,and dark solitons),with a perspective on their potential applications and remaining challenges.展开更多
Dual-comb spectroscopy(DCS) is a powerful tool in molecular spectroscopy benefiting from the advantages of high resolution and short measurement time. The recently developed soliton microcomb(SMC) can potentially tran...Dual-comb spectroscopy(DCS) is a powerful tool in molecular spectroscopy benefiting from the advantages of high resolution and short measurement time. The recently developed soliton microcomb(SMC) can potentially transfer the dual-comb method to an on-chip platform. In this paper, we demonstrate DCS using two frequency scanning SMCs, termed scanning dual-microcomb spectroscopy(SDMCS). The two SMCs are generated by an auxiliary-assisted thermal balance scheme, and the pump laser frequency sweeps over one free spectral range of the microresonator(~49 GHz) using a feedback control system. The proposed SDMCS has a spectral resolution of 12.5 MHz, which is determined by the minimum sweeping step of the pump laser. Using this SDMCS system, we perform three types of gas molecule absorption spectroscopy recognition and gas concentration detection.This study paves the way for integrated DCS with a high signal-to-noise ratio, high spectral resolution, and fast acquisition rate.展开更多
基金funding support from Dream X International Innovation Teamthe support from the startup grant from Nanyang Technological University (022527-00001)。
文摘Mode-locked microcombs with flat spectral profiles provide the high signal-to-noise ratio and are in high demand for wavelength division multiplexing(WDM)-based applications,particularly in future high-capacity communication and parallel optical computing.Here,we present two solutions to generate local relatively flat spectral profiles.One microcavity with ultra-flat integrated dispersion is pumped to generate one relatively flat single soliton source spanning over 150 nm.Besides,one extraordinary soliton crystal with single vacancy demonstrates the local relatively flat microcomb lines when the inner soliton spacings are slightly irregular.Our work paves a new way for soliton-based applications owing to the relatively flat spectral characteristics.
基金This work was supported by the National Key R&D Program of China(Nos.2022YFA1205100,2023YFB2805700,and 2019YFA0705000)the National Natural Science Foundation of China(Nos.62293523 and 12304421)+4 种基金the Leading-edge Technology Program of Jiangsu Natural Science Foundation(No.BK20192001)the Zhangjiang Laboratory(No.ZJSP21A001)the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030009)the Jiangsu Natural Science Foundation(No.BK20230770)the Jiangsu Funding Program for Excellent Postdoctoral Talent.
文摘The optical frequency comb based on microresonators(microcombs)is an integrated coherent light source and has the potential to promise a high-precision frequency standard;self-reference and a long-term stable microcomb are the keys to this realization.Here,we demonstrated a 0.7-octave spectrum Kerr comb via dispersion engineering in a thin-film lithium niobate microresonator,and the single-soliton state can be accessed passively with long-term stability over 3 h.With such a robust broadband coherent comb source using thin-film lithium niobate,a fully stabilized microcomb can be expected for massive practical applications.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.61635013 and 61675231)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB24030600)the Youth Innovation Promotion Association of CAS(Grant No.2016353)。
文摘Optical frequency combs,a revolutionary light source characterized by discrete and equally spaced frequencies,are usually regarded as a cornerstone for advanced frequency metrology,precision spectroscopy,high-speed communication,distance ranging,molecule detection,and many others.Due to the rapid development of micro/nanofabrication technology,breakthroughs in the quality factor of microresonators enable ultrahigh energy buildup inside cavities,which gives birth to microcavity-based frequency combs.In particular,the full coherent spectrum of the soliton microcomb(SMC)provides a route to low-noise ultrashort pulses with a repetition rate over two orders of magnitude higher than that of traditional mode-locking approaches.This enables lower power consumption and cost for a wide range of applications.This review summarizes recent achievements in SMCs,including the basic theory and physical model,as well as experimental techniques for single-soliton generation and various extraordinary soliton states(soliton crystals,Stokes solitons,breathers,molecules,cavity solitons,and dark solitons),with a perspective on their potential applications and remaining challenges.
基金supported by the National Key R&D Program of China(Grant No. 2021YFB2800600)National Natural Science Foundation of China (Grant No. 62075238)。
文摘Dual-comb spectroscopy(DCS) is a powerful tool in molecular spectroscopy benefiting from the advantages of high resolution and short measurement time. The recently developed soliton microcomb(SMC) can potentially transfer the dual-comb method to an on-chip platform. In this paper, we demonstrate DCS using two frequency scanning SMCs, termed scanning dual-microcomb spectroscopy(SDMCS). The two SMCs are generated by an auxiliary-assisted thermal balance scheme, and the pump laser frequency sweeps over one free spectral range of the microresonator(~49 GHz) using a feedback control system. The proposed SDMCS has a spectral resolution of 12.5 MHz, which is determined by the minimum sweeping step of the pump laser. Using this SDMCS system, we perform three types of gas molecule absorption spectroscopy recognition and gas concentration detection.This study paves the way for integrated DCS with a high signal-to-noise ratio, high spectral resolution, and fast acquisition rate.