Our previous work had proved pump field noise coupling in the seed field injected optical parametric amplifier(OPA)at a certain analysis frequency.Inspired by this noise coupling mechanism,the frequency dependent sque...Our previous work had proved pump field noise coupling in the seed field injected optical parametric amplifier(OPA)at a certain analysis frequency.Inspired by this noise coupling mechanism,the frequency dependent squeezing factor due to excess pump noise was experimentally demonstrated.Apart from a reduced squeezing level with an increased noise,the results also prove that a broadband squeezing noise spectrum is not frequency dependent on the amplitude modulated pump field,but limited by the bandwidth of the amplitude modulator and OPA resonator,and the effective measurement is carried out in the frequency range of 2–10 MHz.It provides a guidance to design a broader-bandwidth,higher-level bright squeezed light.展开更多
Parametric interaction allows both forward and backward energy transfers among the three interacting waves.The back-conversion effect is usually detrimental when unidirectional energy transfer is desired.In this theor...Parametric interaction allows both forward and backward energy transfers among the three interacting waves.The back-conversion effect is usually detrimental when unidirectional energy transfer is desired.In this theoretical work,we manifest that the back-conversion effect underpins the direct generation of the picosecond pulse train without the need for a laser resonator.The research scenario is an optical parametric amplification(OPA)that consists of a second-order nonlinear medium,a quasi-continuous pump laser and a sinusoidal amplitude-modulated seed signal.The back-conversion of OPA can transfer the modulation peaks(valleys)of the incident signal into output valleys(peaks),which inherently induces spectral sidebands.The generation of each sideband is naturally accompanied with a phase shift of±π.In the regime of full-back-conversion,the amount and amplitude of the sidebands reach the maximum simultaneously,and their phase constitutes an arithmetic sequence,leading to the production of a picosecond pulse train.The generated picosecond pulse train can have an ultrahigh repetition rate of 40 GHz or higher,which may facilitate ultrafast applications with ultrahigh speed.展开更多
Optical parametric amplification(OPA)represents a powerful solution to achieve broadband amplification in wavelength ranges beyond the scope of conventional gain media,for generating high-power optical pulses,optical ...Optical parametric amplification(OPA)represents a powerful solution to achieve broadband amplification in wavelength ranges beyond the scope of conventional gain media,for generating high-power optical pulses,optical microcombs,entangled photon pairs and a wide range of other applications.Here,we demonstrate optical parametric amplifiers based on silicon nitride(Si3N4)waveguides integrated with two-dimensional(2D)layered graphene oxide(GO)films.We achieve precise control over the thickness,length,and position of the GO films using a transfer-free,layer-by-layer coating method combined with accurate window opening in the chip cladding using photolithography.Detailed OPA measurements with a pulsed pump for the fabricated devices with different GO film thicknesses and lengths show a maximum parametric gain of~24.0 dB,representing a~12.2 dB improvement relative to the device without GO.We perform a theoretical analysis of the device performance,achieving good agreement with experiment and showing that there is substantial room for further improvement.This work represents the first demonstration of integrating 2D materials on chips to enhance the OPA performance,providing a new way of achieving high performance photonic integrated OPA by incorporating 2D materials.展开更多
Non-Hermitian systems have observed numerous novel phenomena and might lead to various applications.Unlike standard quantum physics,the conservation of energy guaranteed by the closed system is broken in the non-Hermi...Non-Hermitian systems have observed numerous novel phenomena and might lead to various applications.Unlike standard quantum physics,the conservation of energy guaranteed by the closed system is broken in the non-Hermitian system,and the energy can be exchanged between the system and the environment.Here we present a scheme for simulating the dissipative phase transition with an open quantum optical system.The competition between the coherent interaction and dissipation leads to the second-order phase transition.Furthermore,the quantum correlation in terms of squeezing is studied around the critical point.Our work may provide a new route to explore the non-Hermitian quantum physics with feasible techniques in experiments.展开更多
Optical vortices,which carry orbital angular momentum,offer special capabilities in a host of applications.A single-laser source with dual-beam-mode output may open up new research fields of nonlinear optics and quant...Optical vortices,which carry orbital angular momentum,offer special capabilities in a host of applications.A single-laser source with dual-beam-mode output may open up new research fields of nonlinear optics and quantum optics.We demonstrate a dual-channel scheme to generate femtosecond,dualwavelength,and dual-beam-mode tunable signals in the near infrared wavelength range.Dual-wavelength operation is derived by stimulating two adjacent periods of a periodically poled lithium niobate crystal.Pumped by an Yb-doped fiber laser with a Gaussian(lp?0)beam,two tunable signal emissions with different beam modes are observed simultaneously.Although one of the emissions can be tuned from1520 to 1613 nm with the Gaussian(ls?0)beam,the other is capable of producing a vortex spatial profile with different vortex orders(ls?0 to 2)tunable from 1490 to 1549 nm.The proposed system provides unprecedented freedom and will be an exciting platform for super-resolution imaging,nonlinear optics,multidimensional quantum entanglement,etc.展开更多
A high repetition rate,picosecond terahertz(THz)parametric amplifier with a LiNbO3(LN)crystai has been demonstrated in this work.At a 10 kHz repetition rate,a peak power of 200 W and an average power of 12 pW have bee...A high repetition rate,picosecond terahertz(THz)parametric amplifier with a LiNbO3(LN)crystai has been demonstrated in this work.At a 10 kHz repetition rate,a peak power of 200 W and an average power of 12 pW have been obtained over a wide range of around 2 THz;at a 100 kHz repetition rate,a maximum peak power of 18 W and an average power of 10.8 pW have been obtained.The parametric gain of the LN crystal was also investigated,and a modified Schwarz-Maier model was introduced to interpret the experimental results.展开更多
基金the National Natural Science Foundation of China(NSFC)(Nos.62027821,11654002,11874250,and 11804207)the National KeyResearch and Development Program of China(No.2020YFC2200402)+3 种基金the KeyResearch and Development Projects of Shanxi Province(No.201903D111001)the Program for Sanjin Scholar of Shanxi ProvincetheProgram for Outstanding Innovative Teams of Higher LearningInstitutions of Shanxithe Fund for Shanxi“1331 Project”KeySubjects Construction。
文摘Our previous work had proved pump field noise coupling in the seed field injected optical parametric amplifier(OPA)at a certain analysis frequency.Inspired by this noise coupling mechanism,the frequency dependent squeezing factor due to excess pump noise was experimentally demonstrated.Apart from a reduced squeezing level with an increased noise,the results also prove that a broadband squeezing noise spectrum is not frequency dependent on the amplitude modulated pump field,but limited by the bandwidth of the amplitude modulator and OPA resonator,and the effective measurement is carried out in the frequency range of 2–10 MHz.It provides a guidance to design a broader-bandwidth,higher-level bright squeezed light.
基金This work was supported by the National Natural Science Foundation of China(Nos.61727820,61905142,61975120,and 91850203).
文摘Parametric interaction allows both forward and backward energy transfers among the three interacting waves.The back-conversion effect is usually detrimental when unidirectional energy transfer is desired.In this theoretical work,we manifest that the back-conversion effect underpins the direct generation of the picosecond pulse train without the need for a laser resonator.The research scenario is an optical parametric amplification(OPA)that consists of a second-order nonlinear medium,a quasi-continuous pump laser and a sinusoidal amplitude-modulated seed signal.The back-conversion of OPA can transfer the modulation peaks(valleys)of the incident signal into output valleys(peaks),which inherently induces spectral sidebands.The generation of each sideband is naturally accompanied with a phase shift of±π.In the regime of full-back-conversion,the amount and amplitude of the sidebands reach the maximum simultaneously,and their phase constitutes an arithmetic sequence,leading to the production of a picosecond pulse train.The generated picosecond pulse train can have an ultrahigh repetition rate of 40 GHz or higher,which may facilitate ultrafast applications with ultrahigh speed.
基金supported by the Australian Research Council Centre of Excellence Project in Optical Microcombs for Breakthrough Science(No.CE230100006)the Australian Research Council Discovery Projects Programs(DP190103186,FT210100806)+5 种基金Linkage Program(LP210200345)the Swinburne ECR-SUPRA program,the Industrial Transformation Training Centers scheme(Grant No.IC180100005)the Beijing Natural Science Foundation(No.Z180007)the Agence Nationale de la Recherche(ANR)(Grant No.MIRSiCOMB,ANR-17-CE24-0028)the H2020 European Research Council(ERC)(Grant No.GRAPHICS,648546)supported by the International Associated Laboratory in Photonics between France and Australia(LIA ALPhFA).
文摘Optical parametric amplification(OPA)represents a powerful solution to achieve broadband amplification in wavelength ranges beyond the scope of conventional gain media,for generating high-power optical pulses,optical microcombs,entangled photon pairs and a wide range of other applications.Here,we demonstrate optical parametric amplifiers based on silicon nitride(Si3N4)waveguides integrated with two-dimensional(2D)layered graphene oxide(GO)films.We achieve precise control over the thickness,length,and position of the GO films using a transfer-free,layer-by-layer coating method combined with accurate window opening in the chip cladding using photolithography.Detailed OPA measurements with a pulsed pump for the fabricated devices with different GO film thicknesses and lengths show a maximum parametric gain of~24.0 dB,representing a~12.2 dB improvement relative to the device without GO.We perform a theoretical analysis of the device performance,achieving good agreement with experiment and showing that there is substantial room for further improvement.This work represents the first demonstration of integrating 2D materials on chips to enhance the OPA performance,providing a new way of achieving high performance photonic integrated OPA by incorporating 2D materials.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61925503, 11874038, and 11654002)the Key Project of the National Key R&D Program of China (Grant Nos. 2016YFA0301402 and 2020YFA0309400)+2 种基金the Program for the Innovative Talents of Higher Education Institutions of Shanxithe Program for Sanjin Scholars of Shanxi Provincethe Fund for Shanxi “1331 Project” Key Subjects Construction
文摘Non-Hermitian systems have observed numerous novel phenomena and might lead to various applications.Unlike standard quantum physics,the conservation of energy guaranteed by the closed system is broken in the non-Hermitian system,and the energy can be exchanged between the system and the environment.Here we present a scheme for simulating the dissipative phase transition with an open quantum optical system.The competition between the coherent interaction and dissipation leads to the second-order phase transition.Furthermore,the quantum correlation in terms of squeezing is studied around the critical point.Our work may provide a new route to explore the non-Hermitian quantum physics with feasible techniques in experiments.
基金support by the National Natural Science Foundation of China(NSFC)(Nos.61535009 and 6182781)the Tianjin Research Program of Application Foundation and Advanced Technology(No.17JCJQJC43500)
文摘Optical vortices,which carry orbital angular momentum,offer special capabilities in a host of applications.A single-laser source with dual-beam-mode output may open up new research fields of nonlinear optics and quantum optics.We demonstrate a dual-channel scheme to generate femtosecond,dualwavelength,and dual-beam-mode tunable signals in the near infrared wavelength range.Dual-wavelength operation is derived by stimulating two adjacent periods of a periodically poled lithium niobate crystal.Pumped by an Yb-doped fiber laser with a Gaussian(lp?0)beam,two tunable signal emissions with different beam modes are observed simultaneously.Although one of the emissions can be tuned from1520 to 1613 nm with the Gaussian(ls?0)beam,the other is capable of producing a vortex spatial profile with different vortex orders(ls?0 to 2)tunable from 1490 to 1549 nm.The proposed system provides unprecedented freedom and will be an exciting platform for super-resolution imaging,nonlinear optics,multidimensional quantum entanglement,etc.
基金the National Key Research and Development Program of China(No.2017YFA0701000)the National Natural Science Foundation of China(No.11735002).
文摘A high repetition rate,picosecond terahertz(THz)parametric amplifier with a LiNbO3(LN)crystai has been demonstrated in this work.At a 10 kHz repetition rate,a peak power of 200 W and an average power of 12 pW have been obtained over a wide range of around 2 THz;at a 100 kHz repetition rate,a maximum peak power of 18 W and an average power of 10.8 pW have been obtained.The parametric gain of the LN crystal was also investigated,and a modified Schwarz-Maier model was introduced to interpret the experimental results.
