Since defects such as traps and oxygen vacancies exist in dielectrics,it is difficult to fabricate a high-performance MoS_(2)field-effect transistor(FET)using atomic layer deposition(ALD)Al_(2)O_(3)as the gate dielect...Since defects such as traps and oxygen vacancies exist in dielectrics,it is difficult to fabricate a high-performance MoS_(2)field-effect transistor(FET)using atomic layer deposition(ALD)Al_(2)O_(3)as the gate dielectric layer.In this paper,NH_(3)in situ doping,a process treatment approach during ALD growth of Al_(2)O_(3),is used to decrease these defects for better device characteristics.MoS_(2)FET has been well fabricated with this technique and the effect of different NH_(3)in situ doping sequences in the growth cycle has been investigated in detail.Compared with counterparts,those devices with NH_(3)in situ doping demonstrate obvious performance enhancements:Ion/Ioff is improved by one order of magnitude,from 1.33×10^(5)to 3.56×10^(6),the threshold voltage shifts from-0.74 V to-0.12 V and a small subthreshold swing of 105 m V/dec is achieved.The improved MoS_(2)FET performance is attributed to nitrogen doping by the introduction of NH_(3)during the Al_(2)O_(3)ALD growth process,which leads to a reduction in the surface roughness of the dielectric layer and the repair of oxygen vacancies in the Al_(2)O_(3)layer.Furthermore,the MoS_(2)FET processed by in situ NH_(3)doping after the Al and O precursor filling cycles demonstrates the best performance;this may be because the final NH_(3)doping after film growth restores more oxygen vacancies to screen more charge scattering in the MoS_(2)channel.The reported method provides a promising way to reduce charge scattering in carrier transport for high-performance MoS_(2)devices.展开更多
We demonstrate a broadband optical parametric oscillation,using a sheet cavity,via cavity phase-matching.A21.2 THz broad comb-like spectrum is achieved,with a uniform line spacing of 133.0 GHz,despite a relatively lar...We demonstrate a broadband optical parametric oscillation,using a sheet cavity,via cavity phase-matching.A21.2 THz broad comb-like spectrum is achieved,with a uniform line spacing of 133.0 GHz,despite a relatively large dispersion of 275.4 fs^(2)/mm around 1064 nm.With 22.6% high slope efficiency,and 14.9 kW peak power handling,this sheet optical parametric oscillator can be further developed for x^((2)) comb.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
The microring resonator based on lithium niobate on insulator(LNOI)is a promising platform for broadband nonlinearity process because of its strong second-order nonlinear coefficients,the capability of dispersion engi...The microring resonator based on lithium niobate on insulator(LNOI)is a promising platform for broadband nonlinearity process because of its strong second-order nonlinear coefficients,the capability of dispersion engineering,etc.It is important to control the energy transmitted into the resonator at different wavelengths,as this becomes difficult for two bands across an octave.In this Letter,we study the effect of different pulley bus-resonator configurations on phase mismatching and mode field overlap.We achieve the control of energy transmission coefficients at different wavebands simultaneously and provide a general design methodology for coupled structures for broadband applications.This paper can contribute to quantum and classical optical broadband applications based on LNOI microring resonators.展开更多
Laser frequency combs emitting ultrafast pulses of light,at equidistantly discrete frequencies,are cornerstones of modern information networks.In recent years,the generation of soliton combs in microcavities with ultr...Laser frequency combs emitting ultrafast pulses of light,at equidistantly discrete frequencies,are cornerstones of modern information networks.In recent years,the generation of soliton combs in microcavities with ultrahighquality factors has established microcombs as out-oflaboratory tools.However,the material and geometry of a laser cavity,which determine comb formation,are difficult to electrically tune.Such dynamic control can further enrich the diversity of comb outputs and help to actively stabilize them.展开更多
Optical parametric oscillators(OPOs) can downconvert the pump laser to longer wavelengths with octave separation via χ^((2)), which is widely used for laser wavelength extension including mid-infrared(MIR) generation...Optical parametric oscillators(OPOs) can downconvert the pump laser to longer wavelengths with octave separation via χ^((2)), which is widely used for laser wavelength extension including mid-infrared(MIR) generation.Such a process can be integrated in monolithic resonators, being compact and low in threshold. In this work, we show that the monolithic χ^((2))mini-OPO can also be used for optical frequency comb generation around 2096 nm and enters the boundary of MIR range. A new geometry called an optical superlattice box resonator is developed for this realization with near-material-limited quality factor of 4.0 × 10^(7). Only a continuous-wave near-infrared pump laser is required, with OPO threshold of 80 mW and output power up to 340 mW. Revival temporal profiles are measured at a detectable repetition frequency of 1.426 GHz, and narrow beat note linewidth of less than 10 Hz shows high comb coherence. These results are in good agreement with our simulation for a stable comb generation. Such an OPO-based comb source is useful for carbon dioxide sensing or the mine prospect applications and can be generalized to longer MIR wavelengths for general gas spectroscopy.展开更多
Optical frequency combs in microresonators(microcombs)have a wide range of applications in science and technology,due to its compact size and access to considerably larger comb spacing.Despite recent successes,the pro...Optical frequency combs in microresonators(microcombs)have a wide range of applications in science and technology,due to its compact size and access to considerably larger comb spacing.Despite recent successes,the problems of self-starting,high mode efficiency as well as high output power have not been fully addressed for conventional soliton microcombs.Recent demonstration of laser cavity soliton microcombs by nesting a microresonator into a fiber cavity,shows great potential to solve the problems.Here we study the dissipative soliton generation and interaction dynamics in a microresonator-fltered fiber laser in both theory and experiment.We bring theoretical insight into the mode-locking principle,discuss the parameters effect on soliton properties,and provide experimental guidelines for broadband soliton generation.We predict chirped bright dissipative soliton with flat-top spectral envelope in microresonators with normal dispersion,which is fundamentally forbidden for the externally driven case.Furthermore,we experimentally achieve soliton microcombs with large bandwidth of~10 nm and high mode efficiency of 90.7%.Finally,by taking advantage of an ultrahigh-speed time magnifier,we study the real-time soliton formation and interaction dynamics and experimentally observe soliton Newton's cradle.Our study will benefit the design of the novel,high-efficiency and self-starting microcombs for real-world applications.展开更多
We report an observation of the second-order correlation between twin beams generated by amplified spontaneous parametric down-conversion operating above threshold with kilowatt-level peak power, from a periodically p...We report an observation of the second-order correlation between twin beams generated by amplified spontaneous parametric down-conversion operating above threshold with kilowatt-level peak power, from a periodically poled Li Ta O3 crystal via a single-pass scheme. Photocurrent correlation was measured because of the bright photon streams, with raw visibility of 37.9% or 97.3% after electronic filtering. As expected in our theory, this correlation is robust and insensitive to parametric gain and detection loss, enabling important applications in optical communications, precision measurement, and nonlocal imaging.展开更多
基金the National Natural Science Foundation of China(Grant Nos.61774168 and 11764008)the Opening Project of Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences。
文摘Since defects such as traps and oxygen vacancies exist in dielectrics,it is difficult to fabricate a high-performance MoS_(2)field-effect transistor(FET)using atomic layer deposition(ALD)Al_(2)O_(3)as the gate dielectric layer.In this paper,NH_(3)in situ doping,a process treatment approach during ALD growth of Al_(2)O_(3),is used to decrease these defects for better device characteristics.MoS_(2)FET has been well fabricated with this technique and the effect of different NH_(3)in situ doping sequences in the growth cycle has been investigated in detail.Compared with counterparts,those devices with NH_(3)in situ doping demonstrate obvious performance enhancements:Ion/Ioff is improved by one order of magnitude,from 1.33×10^(5)to 3.56×10^(6),the threshold voltage shifts from-0.74 V to-0.12 V and a small subthreshold swing of 105 m V/dec is achieved.The improved MoS_(2)FET performance is attributed to nitrogen doping by the introduction of NH_(3)during the Al_(2)O_(3)ALD growth process,which leads to a reduction in the surface roughness of the dielectric layer and the repair of oxygen vacancies in the Al_(2)O_(3)layer.Furthermore,the MoS_(2)FET processed by in situ NH_(3)doping after the Al and O precursor filling cycles demonstrates the best performance;this may be because the final NH_(3)doping after film growth restores more oxygen vacancies to screen more charge scattering in the MoS_(2)channel.The reported method provides a promising way to reduce charge scattering in carrier transport for high-performance MoS_(2)devices.
基金Supported by the National Key Research and Development Program of China(Grant Nos.2019YFA0705000 and 2017YFA0303700)the Key R&D Program of Guangdong Province(Grant No.2018B030329001)+1 种基金the Leading-Edge Technology Program of Jiangsu Natural Science Foundation(Grant No.BK20192001)the National Natural Science Foundation of China(Grant Nos.51890861,11690031,11621091,and 11674169)。
文摘We demonstrate a broadband optical parametric oscillation,using a sheet cavity,via cavity phase-matching.A21.2 THz broad comb-like spectrum is achieved,with a uniform line spacing of 133.0 GHz,despite a relatively large dispersion of 275.4 fs^(2)/mm around 1064 nm.With 22.6% high slope efficiency,and 14.9 kW peak power handling,this sheet optical parametric oscillator can be further developed for x^((2)) comb.
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supported by the National Key R&D Program of China(Nos.2019YFA0705000 and 2017YFA0303700)the Key R&D Program of Guangdong Province(No.2018B030329001)+4 种基金the Leading-edge Technology Program of Jiangsu Natural Science Foundation(No.BK20192001)the National Natural Science Foundation of China(Nos.51890861,11690031,11621091,and 11674169)the Guangdong Major Project of Basic and Applied Basic Research,Zhangjiang Laboratory(No.ZJSP21A001)the China Postdoctoral Science Foundation(No.2022M710068)the Jiangsu Planned Projects for Postdoctoral Research Funds(No.2021K259B)。
文摘The microring resonator based on lithium niobate on insulator(LNOI)is a promising platform for broadband nonlinearity process because of its strong second-order nonlinear coefficients,the capability of dispersion engineering,etc.It is important to control the energy transmitted into the resonator at different wavelengths,as this becomes difficult for two bands across an octave.In this Letter,we study the effect of different pulley bus-resonator configurations on phase mismatching and mode field overlap.We achieve the control of energy transmission coefficients at different wavebands simultaneously and provide a general design methodology for coupled structures for broadband applications.This paper can contribute to quantum and classical optical broadband applications based on LNOI microring resonators.
基金the support from the Education Ministry of China and National Science Foundation of China(61705032,61975025,51890861,51802090,and 61874041).
文摘Laser frequency combs emitting ultrafast pulses of light,at equidistantly discrete frequencies,are cornerstones of modern information networks.In recent years,the generation of soliton combs in microcavities with ultrahighquality factors has established microcombs as out-oflaboratory tools.However,the material and geometry of a laser cavity,which determine comb formation,are difficult to electrically tune.Such dynamic control can further enrich the diversity of comb outputs and help to actively stabilize them.
基金National Key Research and Development Program of China (2019YFA0705000, 2017YFA0303700)Leading-edge Technology Program of Jiangsu Natural Science Foundation (BK20192001)+4 种基金Key R&D Program of Guangdong Province (2018B030329001)National Natural Science Foundation of China (51890861, 11690031,11621091, 11674169)Guangdong Major Project of Basic and Applied Basic ResearchJiangsu Planned Projects for Postdoctoral Research Funds (2021K259B)China Scholarship Council (CSC)。
文摘Optical parametric oscillators(OPOs) can downconvert the pump laser to longer wavelengths with octave separation via χ^((2)), which is widely used for laser wavelength extension including mid-infrared(MIR) generation.Such a process can be integrated in monolithic resonators, being compact and low in threshold. In this work, we show that the monolithic χ^((2))mini-OPO can also be used for optical frequency comb generation around 2096 nm and enters the boundary of MIR range. A new geometry called an optical superlattice box resonator is developed for this realization with near-material-limited quality factor of 4.0 × 10^(7). Only a continuous-wave near-infrared pump laser is required, with OPO threshold of 80 mW and output power up to 340 mW. Revival temporal profiles are measured at a detectable repetition frequency of 1.426 GHz, and narrow beat note linewidth of less than 10 Hz shows high comb coherence. These results are in good agreement with our simulation for a stable comb generation. Such an OPO-based comb source is useful for carbon dioxide sensing or the mine prospect applications and can be generalized to longer MIR wavelengths for general gas spectroscopy.
基金Prof.Juliet Gopinath for lending the high-speed oscilloscope.M.N,,B.L,Y.X,J.Y.and S.-W.H.acknowledge the support from the University of Colorado Boulder,National Science Foundation(OMA 2016244 and ECCS 2048202)Office of Naval Research(N00014-22-1-2224)+5 种基金K.J.,S.Z,and Z.X.acknowledge the support by the National Key R&D Program of China(2019YFA0705000,2017YFA0303700)Key R&D Program of Guangdong Province(2018B030329001)Guangdong Major Project of Basic and Applied Basic Research(2020B0301030009)Zhangjiang Laboratory(ZJSP21A001)Leading-edge technology Program of Jiangsu Natural Science Foundation(BK20192001)National Natural Science Foundation of China(51890861,11690031,11621091,11627810,11674169,91950206).
文摘Optical frequency combs in microresonators(microcombs)have a wide range of applications in science and technology,due to its compact size and access to considerably larger comb spacing.Despite recent successes,the problems of self-starting,high mode efficiency as well as high output power have not been fully addressed for conventional soliton microcombs.Recent demonstration of laser cavity soliton microcombs by nesting a microresonator into a fiber cavity,shows great potential to solve the problems.Here we study the dissipative soliton generation and interaction dynamics in a microresonator-fltered fiber laser in both theory and experiment.We bring theoretical insight into the mode-locking principle,discuss the parameters effect on soliton properties,and provide experimental guidelines for broadband soliton generation.We predict chirped bright dissipative soliton with flat-top spectral envelope in microresonators with normal dispersion,which is fundamentally forbidden for the externally driven case.Furthermore,we experimentally achieve soliton microcombs with large bandwidth of~10 nm and high mode efficiency of 90.7%.Finally,by taking advantage of an ultrahigh-speed time magnifier,we study the real-time soliton formation and interaction dynamics and experimentally observe soliton Newton's cradle.Our study will benefit the design of the novel,high-efficiency and self-starting microcombs for real-world applications.
基金the National Key R&D Program of China(Nos.2019YFA0705000 and 2017YFA0303700)the National Natural Science Foundation of China(Nos.51890861,11690031,11627810,11674169,and 11974178).
文摘We report an observation of the second-order correlation between twin beams generated by amplified spontaneous parametric down-conversion operating above threshold with kilowatt-level peak power, from a periodically poled Li Ta O3 crystal via a single-pass scheme. Photocurrent correlation was measured because of the bright photon streams, with raw visibility of 37.9% or 97.3% after electronic filtering. As expected in our theory, this correlation is robust and insensitive to parametric gain and detection loss, enabling important applications in optical communications, precision measurement, and nonlocal imaging.