The optical rotational Doppler effect associated with orbital angular momentum provides a new means for rotational velocity detection.In this paper,we investigate the influence of atmospheric turbulence on the rotatio...The optical rotational Doppler effect associated with orbital angular momentum provides a new means for rotational velocity detection.In this paper,we investigate the influence of atmospheric turbulence on the rotational Doppler effect.First,we deduce the generalized formula of the rotational Doppler shift in atmospheric turbulence by mode decomposition.It is found that the rotational Doppler signal frequency spectrum will be broadened,and the bandwidth is related to the turbulence intensity.In addition,as the propagation distance increases,the bandwidth also increases.And when C_(n)^(2)≤5×10^(-15)m^(-2/3)and 2z≤2 km,the rotational Doppler signal frequency spectrum width d and the spiral spectrum width d_(0)satisfy the relationship d=2d_(0-1).Finally,we analyze the influence of mode crosstalk on the rotational Doppler effect,and the results show that it destroys the symmetrical distribution of the rotational Doppler spectrum about 2l·Ω/2π.This theoretical model enables us to better understand the generation of the rotational Doppler frequency and may help us better analyze the influence of the complex atmospheric environment on the rotational Doppler frequency.展开更多
The rotational Doppler effect holds significant potential for remote sensing of rotating objects due to its real-time performance and non-contact advantages.A single-ring beam is used to measure rotation speed.To enha...The rotational Doppler effect holds significant potential for remote sensing of rotating objects due to its real-time performance and non-contact advantages.A single-ring beam is used to measure rotation speed.To enhance the signal-to-noise ratio and measure additional parameters,multiple rings are introduced in the context of a rotational Doppler effect.However,the interference between these rings poses a challenge for multitasking detection applications.In this study,cross-polarization superposition was applied to generate an ultra-dense vector perfect vortex beam that exhibited sensitivity to spatial position and object size,and flexibility in designing topological charge combinations for generating frequency combs.A proof-of-principle experiment was conducted to demonstrate its capability in improving the signal-to-noise ratio,and accurately perceiving both the radius of rotation and radial size.An ultra-dense vector perfect vortex beam provides a general strategy for beam construction and the multi-parameter perception of rotating objects,thereby enabling potential applications in the measurement of velocity gradient measurement of fluids.展开更多
We propose a method for detecting the symmetry of rotating patterns based on the rotational Doppler effect(RDE)of light.The basic mechanisms of the RDE are introduced,and the spiral harmonic distribution of rotating p...We propose a method for detecting the symmetry of rotating patterns based on the rotational Doppler effect(RDE)of light.The basic mechanisms of the RDE are introduced,and the spiral harmonic distribution of rotating patterns is analyzed.By irradiating the rotating pattern using a superimposed optical vortex and analyzing the amplitude of the RDE signal,the spiral harmonic distribution of the pattern can be measured,and then its symmetry can be detected.We demonstrate this method experimentally by using patterns with different symmetries and shapes.As the method does not need to receive the scattered light completely and accurately,it promises potential application in detecting symmetrical rotating objects at a long distance.展开更多
Probing the axis of a rotator is important in astrophysics,aerospace,manufacturing,machinery,automation,and virtual reality,etc.Existing optical solutions commonly require multiple sequential measurements via symmetry...Probing the axis of a rotator is important in astrophysics,aerospace,manufacturing,machinery,automation,and virtual reality,etc.Existing optical solutions commonly require multiple sequential measurements via symmetry-broken light fields,which make them time-consuming,inefficient,and prone to accumulated errors.Herein,we propose the concept of a dual-point noncoaxial rotational Doppler effect(DNRDE)and demonstrate a one-shot detection technique to solve this problem.An on-demand synthetic orbital angular momentum(OAM)light beam impinges on a rotating scatterer surface,supporting dual-point rotational Doppler shifts,in which the information of the rotating axis is acquired by comparing these two frequency shifts with a prescribed threshold.The existence of arbitrary dual-point Doppler shifts enables the one-time direct identification of rotating axis orientations,which is fundamentally inaccessible in single-point detection.This robust detection technique is compatible with generalised synthetic OAM light fields by utilising optical modal filters.Compared with traditional approaches,our DNRDE-driven detection approach exhibits a four-fold enhancement in measurement speed,higher energy efficiency,and superior accuracy with a maximal absolute measurement error of 2.23°.The proposed dual-point detection method holds great promise for detecting rotating bodies in various applications,such as astronomical surveys and industrial manufacturing.展开更多
In recent years,with the clarification of the mechanism of the rotational Doppler effect(RDE),there has attracted extensive attention to its development of applications,especially in the detection of the angular veloc...In recent years,with the clarification of the mechanism of the rotational Doppler effect(RDE),there has attracted extensive attention to its development of applications,especially in the detection of the angular velocity of rotating objects.On the other hand,optical fiber technology is widely applied in laser velocimetry from beam delivery to scattered light collection,aiding the miniaturization of instruments.Here we report the first all-fiber rotational Doppler velocimetry(AF-RDV)with a single probe based on a fabricated mode-sculpted fiber-optic element.The constructed AF-RDV can be operated in two reciprocal schemes wherein exchanging the illuminating mode and detected mode.Using this,we experimentally demonstrate the mode-changing dependent nature of the RDE.Particularly,the results suggest that the rotational Doppler shift can be observed by mode-filtering the scattered signal even with a nontwisted probe light.We also show the achromatic property of the RDE by scanning the incident wavelength,enabling the AF-RDV within an ultra-broadband operation range.The AF-RDV exhibits favorable performance for detecting spinning rough surfaces.It may provide an exciting new practical sensing instrument with significant prospects for monitoring angular motion in both research and industry.展开更多
The ability to measure the orbital angular momentum(OAM)distribution of vortex light is essential for OAM applications.Although there have been many studies on the measurement of OAM modes,it is difficult to quantitat...The ability to measure the orbital angular momentum(OAM)distribution of vortex light is essential for OAM applications.Although there have been many studies on the measurement of OAM modes,it is difficult to quantitatively and instantaneously measure the power distribution among different OAM modes,let alone measure the phase distribution among them.In this work,we propose an OAM complex spectrum analyzer that enables simultaneous measurements of the power and phase distributions of OAM modes by employing the rotational Doppler effect.The original OAM mode distribution is mapped to an electrical spectrum of beat signals using a photodetector.The power and phase distributions of superimposed OAM beams are successfully retrieved by analyzing the electrical spectrum.We also extend the measurement technique to other spatial modes,such as linear polarization modes.These results represent a new landmark in spatial mode analysis and show great potential for applications in OAM-based systems and optical communication systems with mode-division multiplexing.展开更多
The expeditious acquisition of information pertaining to objects through the utilization of quantum technology has been a perennial issue of concern.So far,the efficient utilization of information from dynamic objects...The expeditious acquisition of information pertaining to objects through the utilization of quantum technology has been a perennial issue of concern.So far,the efficient utilization of information from dynamic objects with limited resources remains a significant challenge.Here,we realize a nonlocal integrated sensing of the object's amplitude and phase information by combining digital spiral imaging with the correlated orbital angular momentum states.The amplitude information is utilized for object identification,while the phase information enables us to determine the rotational speed.We demonstrate the nonlocal identification of a rotating object's shape,irrespective of its rotational symmetry,and introduce the concept of the correlated rotational Doppler effect,establishing a fundamental connection between this effect and the classical rotational Doppler effect,i.e.,that both rely on extracting crucial information from the spiral spectrum of objects.The present study highlights a promising pathway towards the realization of quantum remote sensing and imaging.展开更多
The detection of angular acceleration has broad applications in remote sensing,including platform attitude control,dynamic target tracking,and environmental monitoring.The rotational Doppler effect of structured light...The detection of angular acceleration has broad applications in remote sensing,including platform attitude control,dynamic target tracking,and environmental monitoring.The rotational Doppler effect of structured light carrying orbital angular momentum has shown great potential for measuring angular velocity.However,when the angular velocity varies,a chirped intensity signal is generated,and the frequency spectrum of traditional RDE analysis broadens,which hinders the accurate extraction of velocity or acceleration information.To address this challenge,fractional rotational Doppler frequency analysis was introduced to measure angular acceleration in cases of variable velocity motion illuminated by conjugate vortex beams.Experimental results demonstrate that fractional rotational Doppler frequency analysis not only effectively handles timevarying signals from accelerating objects,but also exhibits strong resistance to environmental noise and atmospheric turbulence.These advancements hold significant potential for practical applications in fields such as aerospace,deep-sea exploration,and beyond.展开更多
基金Project supported by the Research Plan Project of the National University of Defense Technology(Grant No.ZK18-0102)the National Natural Science Foundation of China(Grant No.61871389)+1 种基金the State Key Laboratory of Pulsed Power Laser Technology(Grant No.KY21C604)the Postgraduate Scientific Research Innovation Project of Hunan Province(Grant Nos.CX20220007 and CX20230024)。
文摘The optical rotational Doppler effect associated with orbital angular momentum provides a new means for rotational velocity detection.In this paper,we investigate the influence of atmospheric turbulence on the rotational Doppler effect.First,we deduce the generalized formula of the rotational Doppler shift in atmospheric turbulence by mode decomposition.It is found that the rotational Doppler signal frequency spectrum will be broadened,and the bandwidth is related to the turbulence intensity.In addition,as the propagation distance increases,the bandwidth also increases.And when C_(n)^(2)≤5×10^(-15)m^(-2/3)and 2z≤2 km,the rotational Doppler signal frequency spectrum width d and the spiral spectrum width d_(0)satisfy the relationship d=2d_(0-1).Finally,we analyze the influence of mode crosstalk on the rotational Doppler effect,and the results show that it destroys the symmetrical distribution of the rotational Doppler spectrum about 2l·Ω/2π.This theoretical model enables us to better understand the generation of the rotational Doppler frequency and may help us better analyze the influence of the complex atmospheric environment on the rotational Doppler frequency.
基金National Key Research and Development Program of China(2022YFA1404800,2019YFA0705000)National Natural Science Foundation of China(12174280,12204340,12192254,92250304,12434012)+3 种基金China Postdoctoral Science Foundation(2022M722325)Priority Academic Program Development of Jiangsu Higher Education InstitutionsJiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB593)Key Lab of Modern Optical Technologies of Jiangsu Province(KJS2138)。
文摘The rotational Doppler effect holds significant potential for remote sensing of rotating objects due to its real-time performance and non-contact advantages.A single-ring beam is used to measure rotation speed.To enhance the signal-to-noise ratio and measure additional parameters,multiple rings are introduced in the context of a rotational Doppler effect.However,the interference between these rings poses a challenge for multitasking detection applications.In this study,cross-polarization superposition was applied to generate an ultra-dense vector perfect vortex beam that exhibited sensitivity to spatial position and object size,and flexibility in designing topological charge combinations for generating frequency combs.A proof-of-principle experiment was conducted to demonstrate its capability in improving the signal-to-noise ratio,and accurately perceiving both the radius of rotation and radial size.An ultra-dense vector perfect vortex beam provides a general strategy for beam construction and the multi-parameter perception of rotating objects,thereby enabling potential applications in the measurement of velocity gradient measurement of fluids.
基金supported by the National Natural Science Foundation of China(Nos.11772001 and 61805283)Key Research Projects of Foundation Strengthening Program(No.2019-JCJQ-ZD)。
文摘We propose a method for detecting the symmetry of rotating patterns based on the rotational Doppler effect(RDE)of light.The basic mechanisms of the RDE are introduced,and the spiral harmonic distribution of rotating patterns is analyzed.By irradiating the rotating pattern using a superimposed optical vortex and analyzing the amplitude of the RDE signal,the spiral harmonic distribution of the pattern can be measured,and then its symmetry can be detected.We demonstrate this method experimentally by using patterns with different symmetries and shapes.As the method does not need to receive the scattered light completely and accurately,it promises potential application in detecting symmetrical rotating objects at a long distance.
基金supported by the National Natural Science Foundation of China(Grant Nos.62075049 and 11974258)the Fundamental Research Funds for the Central Universities(FRFCU5710050722,FRFCU5770500522,FRFCU9803502223,and 2023FRFK06007)supported by the Australian Research Council Centre of Excellence(CE230100006).
文摘Probing the axis of a rotator is important in astrophysics,aerospace,manufacturing,machinery,automation,and virtual reality,etc.Existing optical solutions commonly require multiple sequential measurements via symmetry-broken light fields,which make them time-consuming,inefficient,and prone to accumulated errors.Herein,we propose the concept of a dual-point noncoaxial rotational Doppler effect(DNRDE)and demonstrate a one-shot detection technique to solve this problem.An on-demand synthetic orbital angular momentum(OAM)light beam impinges on a rotating scatterer surface,supporting dual-point rotational Doppler shifts,in which the information of the rotating axis is acquired by comparing these two frequency shifts with a prescribed threshold.The existence of arbitrary dual-point Doppler shifts enables the one-time direct identification of rotating axis orientations,which is fundamentally inaccessible in single-point detection.This robust detection technique is compatible with generalised synthetic OAM light fields by utilising optical modal filters.Compared with traditional approaches,our DNRDE-driven detection approach exhibits a four-fold enhancement in measurement speed,higher energy efficiency,and superior accuracy with a maximal absolute measurement error of 2.23°.The proposed dual-point detection method holds great promise for detecting rotating bodies in various applications,such as astronomical surveys and industrial manufacturing.
基金supported by the National Natural Science Foundation of China(NSFC)(62125503,62261160388)the Natural Science Foundation of Hubei Province of China(2023AFA028).
文摘In recent years,with the clarification of the mechanism of the rotational Doppler effect(RDE),there has attracted extensive attention to its development of applications,especially in the detection of the angular velocity of rotating objects.On the other hand,optical fiber technology is widely applied in laser velocimetry from beam delivery to scattered light collection,aiding the miniaturization of instruments.Here we report the first all-fiber rotational Doppler velocimetry(AF-RDV)with a single probe based on a fabricated mode-sculpted fiber-optic element.The constructed AF-RDV can be operated in two reciprocal schemes wherein exchanging the illuminating mode and detected mode.Using this,we experimentally demonstrate the mode-changing dependent nature of the RDE.Particularly,the results suggest that the rotational Doppler shift can be observed by mode-filtering the scattered signal even with a nontwisted probe light.We also show the achromatic property of the RDE by scanning the incident wavelength,enabling the AF-RDV within an ultra-broadband operation range.The AF-RDV exhibits favorable performance for detecting spinning rough surfaces.It may provide an exciting new practical sensing instrument with significant prospects for monitoring angular motion in both research and industry.
基金supported by the National Basic Research Program of China(Grant No.2011CB301704)the Program for New Century Excellent Talents of the Ministry of Education of China(Grant No.NCET-11-0168)+2 种基金the Foundation for the Author of National Excellent Doctoral Dissertation of China(Grant No.201139)the National Natural Science Foundation of China(Grant No.11174096,11374008,11534008 and 61475052)the Foundation for Innovative Research Groups of the Natural Science Foundation of Hubei Province(Grant No.2014CFA004).
文摘The ability to measure the orbital angular momentum(OAM)distribution of vortex light is essential for OAM applications.Although there have been many studies on the measurement of OAM modes,it is difficult to quantitatively and instantaneously measure the power distribution among different OAM modes,let alone measure the phase distribution among them.In this work,we propose an OAM complex spectrum analyzer that enables simultaneous measurements of the power and phase distributions of OAM modes by employing the rotational Doppler effect.The original OAM mode distribution is mapped to an electrical spectrum of beat signals using a photodetector.The power and phase distributions of superimposed OAM beams are successfully retrieved by analyzing the electrical spectrum.We also extend the measurement technique to other spatial modes,such as linear polarization modes.These results represent a new landmark in spatial mode analysis and show great potential for applications in OAM-based systems and optical communication systems with mode-division multiplexing.
基金supported by the National Natural Science Foundation of China(Grant No.12174301)the Shaanxi Fundamental Science Research Project for Mathematics and Physics(Grant No.22JSQ012)the Natural Science Basic Research Program of Shaanxi(Grant No.2023-JC-JQ01)。
文摘The expeditious acquisition of information pertaining to objects through the utilization of quantum technology has been a perennial issue of concern.So far,the efficient utilization of information from dynamic objects with limited resources remains a significant challenge.Here,we realize a nonlocal integrated sensing of the object's amplitude and phase information by combining digital spiral imaging with the correlated orbital angular momentum states.The amplitude information is utilized for object identification,while the phase information enables us to determine the rotational speed.We demonstrate the nonlocal identification of a rotating object's shape,irrespective of its rotational symmetry,and introduce the concept of the correlated rotational Doppler effect,establishing a fundamental connection between this effect and the classical rotational Doppler effect,i.e.,that both rely on extracting crucial information from the spiral spectrum of objects.The present study highlights a promising pathway towards the realization of quantum remote sensing and imaging.
基金supported by the National Key R&D Program of China (Grant No. 2022YFA1404800)the National Natural Science Foundation of China (Grant Nos. 12174280, 12204340, 12192254, 92250304, 12434012, and W2441005)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Key Lab of Modern Optical Technologies of Jiangsu Province (Grant No. KJS2138)
文摘The detection of angular acceleration has broad applications in remote sensing,including platform attitude control,dynamic target tracking,and environmental monitoring.The rotational Doppler effect of structured light carrying orbital angular momentum has shown great potential for measuring angular velocity.However,when the angular velocity varies,a chirped intensity signal is generated,and the frequency spectrum of traditional RDE analysis broadens,which hinders the accurate extraction of velocity or acceleration information.To address this challenge,fractional rotational Doppler frequency analysis was introduced to measure angular acceleration in cases of variable velocity motion illuminated by conjugate vortex beams.Experimental results demonstrate that fractional rotational Doppler frequency analysis not only effectively handles timevarying signals from accelerating objects,but also exhibits strong resistance to environmental noise and atmospheric turbulence.These advancements hold significant potential for practical applications in fields such as aerospace,deep-sea exploration,and beyond.
