Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lit...Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lithium niobate(TFLN),hailed as“the silicon of photonics,”has emerged as a pivotal material in the realm of chip-scale nonlinear optics,propelling the demand for compact optical isolators.We report a breakthrough in the development of a fully passive,integrated optical isolator on the TFLN platform,leveraging the Kerr effect to achieve an impressive 10.3 dB of isolation with a minimal insertion loss of 1.87 dB.Further theoretical simulations have demonstrated that our design,when applied to a microring resonator with a Q factor of 5×10^(6),can achieve 20 dB of isolation with an input power of merely 8 mW.This advancement underscores the immense potential of lithium niobate-based Kerr-effect isolators in propelling the integration and application of high-performance on-chip lasers,heralding a new era in integrated photonics.展开更多
On-chip optical nonreciprocal devices are vital components for integrated photonic systems and scalable quantum information processing.Nonlinear optical isolators and circulators have attracted considerable attention ...On-chip optical nonreciprocal devices are vital components for integrated photonic systems and scalable quantum information processing.Nonlinear optical isolators and circulators have attracted considerable attention because of their fundamental interest and their important advantages in integrated photonic circuits.However,optical nonreciprocal devices based on Kerr or Kerr-like nonlinearity are subject to dynamical reciprocity when the forward and backward signals coexist simultaneously in a nonlinear system.Here,we theoretically propose a method for realizing on-chip nonlinear isolators and circulators with dynamic nonreciprocity.Dynamic nonreciprocity is achieved via the chiral modulation on the resonance frequency due to coexisting self-and cross-Kerr nonlinearities in an optical ring resonator.This work showing dynamic nonreciprocity with a Kerr nonlinear resonator can be an essential step toward integrated optical isolation.展开更多
Mediated by the interactions with quantum vacuum fields,a probe laser field propagating in a nonlinear optical medium can generate new pair of light fields over a broad spectral range via spontaneous parametric proces...Mediated by the interactions with quantum vacuum fields,a probe laser field propagating in a nonlinear optical medium can generate new pair of light fields over a broad spectral range via spontaneous parametric process.Such process is inherently independent of the incident direction of light and reciprocal thus far,due to the directionindependent field-vacuum interactions.In this work,we experimentally demonstrate within sodium atomic vapors that such spontaneous parametric process can be nonreciprocal by unidirectionally coupling it to another pumped four-wave mixing process.Thanks to the broad bandwidth of the spontaneous parametric process,in combination with the Doppler and power-induced broadening of atomic energy levels,we achieve optical isolation with isolation ratio>25 dB over a bandwidth larger than 100 GHz.Considering that both spontaneous parametric processes and the pumped four-wave mixing have been realized in diverse solid photonic platforms,the demonstrated concept can motivate further explorations in the design of integrated magnetic-free broadband optical nonreciprocity via the interactions between nonlinear optical processes.展开更多
Phonon lasers or coherent amplifications of mechanical oscillations are powerful tools for fundamental studies on coherent acoustics and hold potential for diverse applications,ranging from ultrasensitive force sensin...Phonon lasers or coherent amplifications of mechanical oscillations are powerful tools for fundamental studies on coherent acoustics and hold potential for diverse applications,ranging from ultrasensitive force sensing to phononic information processing.Here,we propose the use of an optomechanical resonator coupled to a nonlinear optical resonator for directional phonon lasing.We find that by pumping the nonlinear optical resonator,directional optical squeezing can occur along the pump direction.As a result,we can achieve the directional mechanical gain using directional optical squeezing,thereby leading to nonreciprocal phonon lasing with a well-tunable directional power threshold.Our work proposes a feasible way to build nonreciprocal phonon lasers with various nonlinear optical media,which are important for a wide range of applications,such as directional acoustic amplifiers,invisible sound sensing or imaging,and one-way phononic networks.展开更多
We investigate the single-photon transport problem in the system of a whispering-gallery mode microresonator chirally coupled with a two-level quantum emitter[QE].Conventionally,this chiral QE-microresonator coupling ...We investigate the single-photon transport problem in the system of a whispering-gallery mode microresonator chirally coupled with a two-level quantum emitter[QE].Conventionally,this chiral QE-microresonator coupling system can be studied by the master equation and the single-photon transport methods.Here,we provide a new approach,based on the transfer matrix,to assess the single-photon transmission of such a system.Furthermore,we prove that these three methods are equivalent.The corresponding relations of parameters among these approaches are precisely deduced.The transfer matrix can be extended to a multiple-resonator system interacting with two-level QEs in a chiral way.Therefore,our work may provide a convenient and intuitive form for exploring more complex chiral cavity quantum electrodynamics systems.展开更多
Nonreciprocal light propagation plays an important role in modern optical systems,from photonic networks to integrated photonics. We propose a nonreciprocal system based on a resonance-frequency-tunable cavity and int...Nonreciprocal light propagation plays an important role in modern optical systems,from photonic networks to integrated photonics. We propose a nonreciprocal system based on a resonance-frequency-tunable cavity and intensity-adaptive feedback control. Because the feedback-induced Kerr nonlinearity in the cavity is dependent on the incident direction of light,the system exhibits nonreciprocal transmission with a transmission contrast of 0.99 and an insertion loss of 1.5 dB. By utilizing intensity-adaptive feedback control,the operating intensity range of the nonreciprocal system is broadened to 20 dB,which relaxes the limitation of the operating intensity range for nonlinear nonreciprocal systems. Our protocol paves the way to realize high-performance nonreciprocal propagation in optical systems and can also be extended to microwave systems.展开更多
Chirality,defined by Lord Kelvin,refers to the geometric symmetry property of an object that cannot be superposed onto its mirror image using rotations and translations.The material’s chirality can be probed with lig...Chirality,defined by Lord Kelvin,refers to the geometric symmetry property of an object that cannot be superposed onto its mirror image using rotations and translations.The material’s chirality can be probed with light as the optical activity:optical rotary dispersion(ORD)and circular dichroism(CD).It is still challenging to yield extremely sensitive ORD and CD for very weak chirality and measure both simultaneously.Cavity ringdown polarimetry has been reported to improve ORD detection sensitivity with the absence of equally important CD signature,at the price of high cavity finesse near 400,frequency-locking sophistication,and large magnetic field.Here,we report a unique recipe to demonstrate the simultaneous measurement of ORD and the CD by separately observing the chiral eigenmode spectra from a bowtie optical cavity with a finesse about 30,without resorting to frequency locking or magnetic field.We obtain a sensitivity of2.7×10^(−3)deg/√Hz for ORD,8.1×10^(−6)/√Hz for CD,and a spectral resolution of 0.04 pm within a millisecond-scale measurement.We present a cost-effective yet ultrasensitive account for chiral chromatography,the conformational dynamics and chiroptical analysis of biological samples which particularly exhibit weak and narrow spectral signals.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2022YFF0712800 and 2019YFA0308700)。
文摘Optical isolators,the photonic analogs of electronic diodes,are essential for ensuring the unidirectional flow of light in optical systems,thereby mitigating the destabilizing effects of back reflections.Thin-film lithium niobate(TFLN),hailed as“the silicon of photonics,”has emerged as a pivotal material in the realm of chip-scale nonlinear optics,propelling the demand for compact optical isolators.We report a breakthrough in the development of a fully passive,integrated optical isolator on the TFLN platform,leveraging the Kerr effect to achieve an impressive 10.3 dB of isolation with a minimal insertion loss of 1.87 dB.Further theoretical simulations have demonstrated that our design,when applied to a microring resonator with a Q factor of 5×10^(6),can achieve 20 dB of isolation with an input power of merely 8 mW.This advancement underscores the immense potential of lithium niobate-based Kerr-effect isolators in propelling the integration and application of high-performance on-chip lasers,heralding a new era in integrated photonics.
基金supported by the National Key R&D Program of China(Grant Nos.2017YFA0303703 and 2019YFA0308700)the National Natural Science Foundation of China(Grant Nos.11874212,11890704,and 11690031)+7 种基金the Fundamental Research Funds for the Central Universities(Grant No.021314380095)the Program for Innovative Talents and Entrepreneurs in Jiangsuthe Excellent Research Program of Nanjing University(Grant No.ZYJH002)supported in part by Nippon Telegraph and Telephone Corporation(NTT)Research,the Japan Science and Technology Agency(JST)(via the Quantum Leap Flagship Program(Q-LEAP),and the Moonshot R&D under Grant No.JPMJMS2061)the Japan Society for the Promotion of Science(JSPS)(via the Grants-in-Aid for Scientific Research(KAKENHI)Grant No.JP20H00134)the Army Research Office(ARO)(Grant No.W911NF-181-0358)the Asian Office of Aerospace Research and Development(AOARD)(Grant No.FA2386-20-1-4069)the Foundational Questions Institute Fund(FQXi)(Grant No.FQXi-IAF19-06)。
文摘On-chip optical nonreciprocal devices are vital components for integrated photonic systems and scalable quantum information processing.Nonlinear optical isolators and circulators have attracted considerable attention because of their fundamental interest and their important advantages in integrated photonic circuits.However,optical nonreciprocal devices based on Kerr or Kerr-like nonlinearity are subject to dynamical reciprocity when the forward and backward signals coexist simultaneously in a nonlinear system.Here,we theoretically propose a method for realizing on-chip nonlinear isolators and circulators with dynamic nonreciprocity.Dynamic nonreciprocity is achieved via the chiral modulation on the resonance frequency due to coexisting self-and cross-Kerr nonlinearities in an optical ring resonator.This work showing dynamic nonreciprocity with a Kerr nonlinear resonator can be an essential step toward integrated optical isolation.
基金supported by National Natural Science Foundation of China(Grant Nos.62475209,62022066,12074306 and 92365107)the National Key R&D Program of China(Grant No.2019YFA0308700)+2 种基金Qinchuangyuan“Scientist+Engineer”Team Construction of Shaanxi Province(Grant No.2024QCY-KXJ-178)Key Scientific and Technological Innovation Team of Shaanxi Province(2021TD-56)the Program for Innovative Talents and Teams in Jiangsu(Grant No.JSSCTD202138).
文摘Mediated by the interactions with quantum vacuum fields,a probe laser field propagating in a nonlinear optical medium can generate new pair of light fields over a broad spectral range via spontaneous parametric process.Such process is inherently independent of the incident direction of light and reciprocal thus far,due to the directionindependent field-vacuum interactions.In this work,we experimentally demonstrate within sodium atomic vapors that such spontaneous parametric process can be nonreciprocal by unidirectionally coupling it to another pumped four-wave mixing process.Thanks to the broad bandwidth of the spontaneous parametric process,in combination with the Doppler and power-induced broadening of atomic energy levels,we achieve optical isolation with isolation ratio>25 dB over a bandwidth larger than 100 GHz.Considering that both spontaneous parametric processes and the pumped four-wave mixing have been realized in diverse solid photonic platforms,the demonstrated concept can motivate further explorations in the design of integrated magnetic-free broadband optical nonreciprocity via the interactions between nonlinear optical processes.
基金supported by the National Natural Science Foundation of China(Grant No.11935006)the Hunan Provincial Major Sci-Tech Program(Grant No.2023ZJ1010)+10 种基金the Science and Technology Innovation Program of Hunan Province(Grant No.2020RC4047)supported by the National Natural Science Foundation of China(Grant Nos.12247105,12175060,and 11935006)XJ-Lab Key Project(Grant No.23XJ02001).Keyu Xia was supported by the National Key R&D Program of China(Grant No.2019YFA0308704)the National Natural Science Foundation of China(Grant No.92365107)the Program for Innovative Talents and Teams in Jiangsu(Grant No.JSSCTD202138)supported by the National Natural Science Foundation of China(Grant No.12205054)the Jiangxi Provincial Education Office Natural Science Fund Project(Grant No.GJJ211437)the Ph.D.Research Foundation(Grant No.BSJJ202122)supported by the National Natural Science Foundation of China(Grant No.12265004)supported by the National Natural Science Foundation of China(Grant No.12205256)the Henan Provincial Science and Technology Research Project(GrantNo.232102221001)。
文摘Phonon lasers or coherent amplifications of mechanical oscillations are powerful tools for fundamental studies on coherent acoustics and hold potential for diverse applications,ranging from ultrasensitive force sensing to phononic information processing.Here,we propose the use of an optomechanical resonator coupled to a nonlinear optical resonator for directional phonon lasing.We find that by pumping the nonlinear optical resonator,directional optical squeezing can occur along the pump direction.As a result,we can achieve the directional mechanical gain using directional optical squeezing,thereby leading to nonreciprocal phonon lasing with a well-tunable directional power threshold.Our work proposes a feasible way to build nonreciprocal phonon lasers with various nonlinear optical media,which are important for a wide range of applications,such as directional acoustic amplifiers,invisible sound sensing or imaging,and one-way phononic networks.
基金supported by the National Key R&D Program of China(Nos.2019YFA0308700,2017YFA0303703,and 2017YFA0303701)the National Natural Science Foundation of China(Nos.11874212 and 11890704)+1 种基金the Fundamental Research Funds for the Central Universities(No.021314380095)the Program for Innovative Talents and Entrepreneurs in Jiangsu(No.JSSCTD202138)。
文摘We investigate the single-photon transport problem in the system of a whispering-gallery mode microresonator chirally coupled with a two-level quantum emitter[QE].Conventionally,this chiral QE-microresonator coupling system can be studied by the master equation and the single-photon transport methods.Here,we provide a new approach,based on the transfer matrix,to assess the single-photon transmission of such a system.Furthermore,we prove that these three methods are equivalent.The corresponding relations of parameters among these approaches are precisely deduced.The transfer matrix can be extended to a multiple-resonator system interacting with two-level QEs in a chiral way.Therefore,our work may provide a convenient and intuitive form for exploring more complex chiral cavity quantum electrodynamics systems.
基金National Key Research and Development Program of China (2019YFA0308700,2017YFA0303703)National Natural Science Foundation of China (11574145,11690031,11874212,11890704,61671279)+1 种基金Fundamental Research Funds for the Central Universities (021314380095)Program for Innovative Talents and Entrepreneurs in Jiangsu。
文摘Nonreciprocal light propagation plays an important role in modern optical systems,from photonic networks to integrated photonics. We propose a nonreciprocal system based on a resonance-frequency-tunable cavity and intensity-adaptive feedback control. Because the feedback-induced Kerr nonlinearity in the cavity is dependent on the incident direction of light,the system exhibits nonreciprocal transmission with a transmission contrast of 0.99 and an insertion loss of 1.5 dB. By utilizing intensity-adaptive feedback control,the operating intensity range of the nonreciprocal system is broadened to 20 dB,which relaxes the limitation of the operating intensity range for nonlinear nonreciprocal systems. Our protocol paves the way to realize high-performance nonreciprocal propagation in optical systems and can also be extended to microwave systems.
基金supported by the National Key R&D Program of China(Grants No.2022YFA1405000,No.2019YFA0308700)the National Natural Science Foundation of China(Grants No.92365107,No.12305020,and No.11890704)+5 种基金the Program for Innovative Talents and Teams in Jiangsu(Grant No.JSSCTD202138)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301400)China Postdoctoral Science Foundation(Grant No.2023M731613)Jiangsu Funding Program for Excellent Postdoctoral Talent(Grant No.2023ZB708)C.-W.Q.is supported by the Competitive Research Program Award(NRF-CRP22-2019-0006&NRF-CRP26-2021-0004)from the NRF,Prime Minister’s Office,Singaporeby a grant(A-0005947-16-00)from A*STAR MTC IRG(M22K2c0088 with A-8001322-00-00).
文摘Chirality,defined by Lord Kelvin,refers to the geometric symmetry property of an object that cannot be superposed onto its mirror image using rotations and translations.The material’s chirality can be probed with light as the optical activity:optical rotary dispersion(ORD)and circular dichroism(CD).It is still challenging to yield extremely sensitive ORD and CD for very weak chirality and measure both simultaneously.Cavity ringdown polarimetry has been reported to improve ORD detection sensitivity with the absence of equally important CD signature,at the price of high cavity finesse near 400,frequency-locking sophistication,and large magnetic field.Here,we report a unique recipe to demonstrate the simultaneous measurement of ORD and the CD by separately observing the chiral eigenmode spectra from a bowtie optical cavity with a finesse about 30,without resorting to frequency locking or magnetic field.We obtain a sensitivity of2.7×10^(−3)deg/√Hz for ORD,8.1×10^(−6)/√Hz for CD,and a spectral resolution of 0.04 pm within a millisecond-scale measurement.We present a cost-effective yet ultrasensitive account for chiral chromatography,the conformational dynamics and chiroptical analysis of biological samples which particularly exhibit weak and narrow spectral signals.
