Because of its light weight, broadband, and adaptable properties, smart material has been widely applied in the active vibration control （AVC） of flexible structures. Based on a firstorder shear deformation theory, ...Because of its light weight, broadband, and adaptable properties, smart material has been widely applied in the active vibration control （AVC） of flexible structures. Based on a firstorder shear deformation theory, by coupling the electrical and mechanical operation, a 4-node quadrilateral piezoelectric composite element with 24 degrees of freedom for generalized displacements and one electrical potential degree of freedom per piezoelectric layer was derived. Dynamic characteristics of a beam with discontinuously distributed piezoelectric sensors and actuators were presented. A linear quadratic regulator （LQR） feedback controller was designed to suppress the vibration of the beam in the state space using the high precise direct （HPD） integration method.展开更多
Narrow linewidth stabilized lasers are central to precision applications that operate across the visible to short-wave infrared wavelengths,including optical clocks,quantum sensing and computing,ultra-low noise microw...Narrow linewidth stabilized lasers are central to precision applications that operate across the visible to short-wave infrared wavelengths,including optical clocks,quantum sensing and computing,ultra-low noise microwave generation,and fiber sensing.Today,these spectrally pure sources are realized using multiple external cavity tabletop lasers locked to bulk-optic free-space reference cavities.Integration of this technology will enable portable precision applications with improved reliability and robustness.Here,we report wavelength-flexible design and operation,over more than an octave span,of an integrated coil-resonator-stabilized Brillouin laser architecture.Leveraging a versatile two-stage noise reduction approach,we achieve low linewidths and high stability with chip-scale laser designs based on the ultra-low-loss,CMOS-compatible silicon nitride platform.We report operation at 674 and 698 nm for applications to strontium neutral and trapped-ion clocks,quantum sensing and computing,and at 1550 nm for applications to fiber sensing and ultra-low phase noise microwave generation.Over this range we demonstrate frequency noise reduction from 1 to 10 MHz resulting in 1.0-17 Hz fundamental and 181-630 Hz integral linewidths and an Allan deviation of 6.5×10^(-13)at 1ms for 674 nm,6.0×10^(-13)at 15ms for 698 nm,and 2.6×10^(-13)at 15 ms for 1550 nm.This work demonstrates the lowest fundamental and integral linewidths and highest stability achieved to date for stabilized Brillouin lasers with integrated coil-resonator references,with over an order of magnitude improvement in the visible wavelength range.These results unlock the potential of integrated,ultra-low-phase-noise stabilized lasers for precision applications and further integration in systems-on-chip solutions.展开更多
Optical frequency division(OFD)produces low-noise microwave and millimeter-wave(mmWave)signals by transferring the exceptional stability of optical references to electronic frequency domains.Recent developments in int...Optical frequency division(OFD)produces low-noise microwave and millimeter-wave(mmWave)signals by transferring the exceptional stability of optical references to electronic frequency domains.Recent developments in integrated optical references and soliton microcombs have paved the way for miniaturizing OFD oscillators to chip scale.Critical to this realization is a rapid tunable frequency comb that is stabilized to the optical references,thereby coherently linking optical and electronic frequencies.In this work,we advance the on-chip OFD technology using an integrated high-speed lead zirconate titanate(PZT)stress-optic actuator on the SiN soliton microcomb resonator.The integrated PZT actuator tunes the resonance frequency of the soliton-generating microresonator with a bandwidth exceeding 10s MHz and thus adjusts the soliton repetition rate.Optical frequency division and low-noise mmWave generation are demonstrated by feedback control of the soliton repetition rate through the integrated PZT-actuator,and the soliton microcomb is stabilized to a pair of reference lasers that are locked to an integrated 4 m SiN coil reference cavity.Our approach provides a fast,versatile,and integrated control mechanism for OFD oscillators and their applications in advanced communications,sensing,and precise timing.展开更多
Ultra-high-quality-factor(Q)resonators are a critical component for visible to near-infrared(NIR)applications,including quantum sensing and computation,atomic timekeeping and navigation,precision metrology,microwave p...Ultra-high-quality-factor(Q)resonators are a critical component for visible to near-infrared(NIR)applications,including quantum sensing and computation,atomic timekeeping and navigation,precision metrology,microwave photonics,and fiber optic sensing and communications.Implementing such resonators in an ultra-low-loss CMOS foundry compatible photonic integration platform can enable the transitioning of critical components from the lab-to the chip-scale,such as ultra-low-linewidth lasers,optical reference cavities,scanning spectroscopy,and precision filtering.The optimal operation of these resonators must preserve the ultra-low losses and simultaneously support the desired variations in coupling over a wide range of visible and NIR wavelengths as well as provide tolerance to fabrication imperfections.We report a significant advancement in high-performance integrated resonators based on a two-point-coupling design that achieves critical coupling simultaneously at multiple wavelengths across wide wavebands and tuning of the coupling condition at any wavelength,from under-,through critically,to over-coupled.We demonstrate critical coupling at 698 nm and 780 nm in one visible-wavelength resonator and critical coupling over a wavelength range from 1550 nm to 1630 nm in a 340-million intrinsic Q 10-meter-coil waveguide resonator.Using the 340-million intrinsic Q coil resonator,we demonstrate laser stabilization that achieves six orders of magnitude reduction in the semiconductor laser frequency noise.We also report that this design can be used as a characterization technique to measure the intrinsic waveguide losses from 1300 nm to 1650 nm,resolving hydrogen-related absorption peaks at 1380 nm and 1520 nm in the resonator,giving insight to further reduce waveguide loss.The CMOS foundry compatibility of this resonator design will provide a path towards scalable system-on-chip integration for high-performance precision experiments and applications,improving reliability,and reducing size and cost.展开更多
基金Supported by the National Natural Science Foundation of China （51079027）.
文摘Because of its light weight, broadband, and adaptable properties, smart material has been widely applied in the active vibration control （AVC） of flexible structures. Based on a firstorder shear deformation theory, by coupling the electrical and mechanical operation, a 4-node quadrilateral piezoelectric composite element with 24 degrees of freedom for generalized displacements and one electrical potential degree of freedom per piezoelectric layer was derived. Dynamic characteristics of a beam with discontinuously distributed piezoelectric sensors and actuators were presented. A linear quadratic regulator （LQR） feedback controller was designed to suppress the vibration of the beam in the state space using the high precise direct （HPD） integration method.
基金supported by DARPA GRYPHON,under Award Number HR0011-22-2-0008by the U.S.Army Research Office under contract/grant number W911NF2310179+1 种基金by the NSF under Award Number 2016244by a gift from Thorlabs.
文摘Narrow linewidth stabilized lasers are central to precision applications that operate across the visible to short-wave infrared wavelengths,including optical clocks,quantum sensing and computing,ultra-low noise microwave generation,and fiber sensing.Today,these spectrally pure sources are realized using multiple external cavity tabletop lasers locked to bulk-optic free-space reference cavities.Integration of this technology will enable portable precision applications with improved reliability and robustness.Here,we report wavelength-flexible design and operation,over more than an octave span,of an integrated coil-resonator-stabilized Brillouin laser architecture.Leveraging a versatile two-stage noise reduction approach,we achieve low linewidths and high stability with chip-scale laser designs based on the ultra-low-loss,CMOS-compatible silicon nitride platform.We report operation at 674 and 698 nm for applications to strontium neutral and trapped-ion clocks,quantum sensing and computing,and at 1550 nm for applications to fiber sensing and ultra-low phase noise microwave generation.Over this range we demonstrate frequency noise reduction from 1 to 10 MHz resulting in 1.0-17 Hz fundamental and 181-630 Hz integral linewidths and an Allan deviation of 6.5×10^(-13)at 1ms for 674 nm,6.0×10^(-13)at 15ms for 698 nm,and 2.6×10^(-13)at 15 ms for 1550 nm.This work demonstrates the lowest fundamental and integral linewidths and highest stability achieved to date for stabilized Brillouin lasers with integrated coil-resonator references,with over an order of magnitude improvement in the visible wavelength range.These results unlock the potential of integrated,ultra-low-phase-noise stabilized lasers for precision applications and further integration in systems-on-chip solutions.
基金Defense Advanced Research Projects Agency(HR0011-22-2-0008,N660012424000)National Science Foundation(2023775)。
文摘Optical frequency division(OFD)produces low-noise microwave and millimeter-wave(mmWave)signals by transferring the exceptional stability of optical references to electronic frequency domains.Recent developments in integrated optical references and soliton microcombs have paved the way for miniaturizing OFD oscillators to chip scale.Critical to this realization is a rapid tunable frequency comb that is stabilized to the optical references,thereby coherently linking optical and electronic frequencies.In this work,we advance the on-chip OFD technology using an integrated high-speed lead zirconate titanate(PZT)stress-optic actuator on the SiN soliton microcomb resonator.The integrated PZT actuator tunes the resonance frequency of the soliton-generating microresonator with a bandwidth exceeding 10s MHz and thus adjusts the soliton repetition rate.Optical frequency division and low-noise mmWave generation are demonstrated by feedback control of the soliton repetition rate through the integrated PZT-actuator,and the soliton microcomb is stabilized to a pair of reference lasers that are locked to an integrated 4 m SiN coil reference cavity.Our approach provides a fast,versatile,and integrated control mechanism for OFD oscillators and their applications in advanced communications,sensing,and precise timing.
基金DARPA Microsystems Technology Office(HR0011-22-2-0008)Army Research Office(W911NF-23-1-0179).
文摘Ultra-high-quality-factor(Q)resonators are a critical component for visible to near-infrared(NIR)applications,including quantum sensing and computation,atomic timekeeping and navigation,precision metrology,microwave photonics,and fiber optic sensing and communications.Implementing such resonators in an ultra-low-loss CMOS foundry compatible photonic integration platform can enable the transitioning of critical components from the lab-to the chip-scale,such as ultra-low-linewidth lasers,optical reference cavities,scanning spectroscopy,and precision filtering.The optimal operation of these resonators must preserve the ultra-low losses and simultaneously support the desired variations in coupling over a wide range of visible and NIR wavelengths as well as provide tolerance to fabrication imperfections.We report a significant advancement in high-performance integrated resonators based on a two-point-coupling design that achieves critical coupling simultaneously at multiple wavelengths across wide wavebands and tuning of the coupling condition at any wavelength,from under-,through critically,to over-coupled.We demonstrate critical coupling at 698 nm and 780 nm in one visible-wavelength resonator and critical coupling over a wavelength range from 1550 nm to 1630 nm in a 340-million intrinsic Q 10-meter-coil waveguide resonator.Using the 340-million intrinsic Q coil resonator,we demonstrate laser stabilization that achieves six orders of magnitude reduction in the semiconductor laser frequency noise.We also report that this design can be used as a characterization technique to measure the intrinsic waveguide losses from 1300 nm to 1650 nm,resolving hydrogen-related absorption peaks at 1380 nm and 1520 nm in the resonator,giving insight to further reduce waveguide loss.The CMOS foundry compatibility of this resonator design will provide a path towards scalable system-on-chip integration for high-performance precision experiments and applications,improving reliability,and reducing size and cost.
