Dispersive Fourier transform based dual-comb ranging

doi:10.21203/rs.3.rs-3468601/v1

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Dispersive Fourier transform based dual-comb ranging

https://doi.org/10.21203/rs.3.rs-3468601/v1

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published 11 Jun, 2024

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Laser-based light detection and ranging (LIDAR) offering a powerful tool to real-timely map spatial information with exceptional accuracy, owns various applications ranging from industrial manufacturing, remote sensing, to airborne and in-vehicle missions. Over the past two decades, the rapid advancements of optical frequency combs have ushered in a new era for LIDAR, promoting measurement precision to quantum noise limited level. For comb LIDAR systems, to further improve the comprehensive performances and reconcile inherent conflicts between speed, accuracy, and ambiguity range, innovative demodulation strategies become crucial. Here we report a dispersive Fourier transform (DFT) based LIDAR method utilizing phase-locked Vernier dual soliton laser combs. We demonstrate that after in-line pulse stretching, the delay of the flying pulses can be identified via the DFT-based spectrally interferometric measurement instead of pulse-fitting in time domain. This enables absolute distance measurements with precision starting from 262 nm in single shot, to 2.8 nm after averaging 1041 times, in a non-ambiguity range over 1.7 km. Furthermore, our DFT-based LIDAR method distinctly demonstrates an ability to completely eliminate dead zones. Such an integration of frequency-resolved ultrafast analysis and dual comb ranging technology may pave a way for the design of future LIDAR systems.

Physical sciences/Optics and photonics/Lasers, LEDs and light sources/Mode-locked lasers

Physical sciences/Optics and photonics/Optical techniques/Optical spectroscopy

Physical sciences/Optics and photonics/Other photonics/Frequency combs

Physical sciences/Optics and photonics/Other photonics/Optical metrology

Originating from the physical principle of measuring the optical interference [¹] or the time of flight (TOF) [²], laser-based light detection and ranging (LIDAR) [³] has become an integral technology in industrial and scientific metrology. It offers high-precision, extensive range, and fast acquisition [⁴,⁵]. Over recent decades, the advent of the optical frequency comb has delivered unrivalled rulers for ultra-precise time-frequency measurements [⁶]. Specifically, Frequency combs intrinsically generate highly coherent pulse sequences, yielding revolutionary light sources for absolute distance and displacement detection [⁷,⁸,⁹]. Recently, the comb stabilization technology has pushed the light towards the level of “photonic clock” [¹⁶,¹⁷,¹⁸], which enables ultrahigh accuracy for LIDARs [¹⁵,¹⁹,²⁰,²¹]. Besides, rapid progress of microcomb technology [²²,²³] opens a way to miniaturized optical ranging [²⁴]. Microcombs with repetition rates tens to hundreds gigahertz [²⁵,²⁶], enable the acquisition rate higher than 100 MHz [²⁷]. Moreover, the frequency channels of a microcomb can be conveniently filtered-out as frequency modulation continuous-waves [¹⁰,¹¹,¹²] or chaotic waves [¹³,¹⁴], further support massively parallel ranging. In addition to using one single comb, for taking full advantage of the comb spectra meanwhile breaking the bandwidth limits of optical spectrometers, dual-comb-based systems with high-resolution time-resolved interferograms [²⁸], demonstrate the capability to combine both high accuracy and large non-ambiguity range (NAR) for LIDARs [²⁹,³⁰,³¹]. In many cases, the phase-locked dual-comb can even be generated in one cavity (either a fiber-loop or a microresonator) [³²,³³,³⁴,³⁵], further suppresses the common noise. However, the performance of a dual comb ranging system is not only contingent on the uncertainty of the light sources, but also heavily influenced by the resolution of the signal demodulation strategy [³⁶]. The conventional TOF schemes, based on the identification of pulse overlaps, commonly presents an inherent conflict: increasing the dual comb repetition difference enhances the measurement speed, but at the cost of reduced pulse fitting accuracy. Moreover, in conventional dual comb ranging techniques, it is often challenging to circumvent dead-zones [³⁷,³⁸].

Here, for the first time, we introduce the dispersive Fourier transform (DFT) concept into a dual comb ranging system and achieve the stretched pulse-to-pulse spectrally interferometric analysis for the TOF measurements. This scheme enables absolute distance measurement via one-single-shot acquisition without the need of repeatedly sampling the pulse train [³⁹,⁴⁰,⁴¹]. Since the accuracy of the DFT is irrelevant to the parametric design of frequency comb, the achieved performance features both high detection speed and extreme precision. Experimental results demonstrate that we can achieve 262 nm ranging accuracy in single shot, and the ranging accuracy reaches 2.8 nm after averaging 1041 times. Leveraging the dual comb based Vernier effect [³¹,⁴²], the NAR can be extended to 1.7 km. That suggests the distance-precision ratio is approaching 10¹². Moreover, since this method uniquely does not require solving pulse envelopes, the probe-reference pulse offset can be precisely obtained when they are very close, thus completely eliminate dead-zones [⁴³]. We successfully use this system in high-precision morphology measurement and real-time detection of fast dynamic motion. Such a unique combination of dual comb ranging and DFT keeps the high scalability of the dual comb Vernier, transforms the time-of-flight based ranging mechanism from temporal separation to spectral interferogram, and thus overcomes the trade-off between speed and accuracy. It may provide a new platform for broad applications ranging from positioning, imaging, to deformation analyzing.

Figure 1a illustrates the conceptual design of our DFT based dual comb vernier rangefinder. To measure the TOF of optical pulses, we utilize two phase-locked soliton fiber laser combs, one as the signal comb and the other as the local comb. Among them, the signal comb is divided into two paths, one is used as a probe, and the other as a reference. At the receiving terminal, we analyze the synthesized signal carrying ranging information through the DFT. The two laser combs have slightly different repetition rate Δf_r, which enables us to realize a maximum NAR = c/2Δf_r by conveniently swapping the signal comb with repetition rate f_r1 and local comb with repetition rate f_r2 [²⁴], here c is the light velocity. Figure 1b shows the operation principle. In a dual comb ranging system, the TOF Δτ is enlarged to be Δt = mΔτ, here m = f_r1/Δf_r, also known as the zooming factor. In this operation, the sampling step ΔT equals to |1/f_r1 – 1/f_r2| = Δf_r/f_r1f_r2, while the sampling period T_update is 1/Δf_r. The measured distance L = cΔτ/2.

In conventional dual comb ranging methods, the Δτ was typically estimated via fitting the interferometric pulse envelope. In this case, for meeting the Nyquist sampling theorem, there is an inherent limitation Δf_r < f_r1f_r2/2B, here B is the 3-dB spectral bandwidth of the dual comb. This is a main reason that typical fiber dual comb system cannot measure rapidly. On the other hand, in practice, f_r1 and f_r2 are not necessarily integer multiples of their repetition frequency difference (i.e. m is not an integer), thus their pulses are difficult to be strictly aligned in the time domain. Specifically, the pulse-to-pulse offsets could be τ₁ to τ₄, here τ₁ + τ₂ = τ₃ + τ₄ = ΔT. As Fig. 1b shows, the left side (blue box) shows the region that the reference pulses overlap with the local pulses, while the right region (red box) shows the region that the returned probe pulses with a TOF delay overlap with the local pulses, the accurate TOF Δτ = T_r1 – N(T₁-T₂) + τ₁ – τ₃, or Δτ = T_r2 – N(T₁-T₂) + τ₂ – τ₄. More calculations are shown in supplementary note S1. Therefore, the distance to be measured can be expressed as:

$$L=\frac{{({T_{r1}} - N\Delta {T_r}+{\tau _1} - {\tau _3})c}}{2}=\frac{{({T_{r2}} - N\Delta {T_r}+{\tau _2} - {\tau _4})c}}{2}$$

In our scheme, we break the Nyquist’s limitation and realize the measurement of τ₁ to τ₄ with extremely high resolution. In dual comb ranging system, to identify τ₁ to τ₄ is not easy, as commonly they are too small (e.g., down to fs level) to well detect, but the DFT offers a way to obtain high quality pulse-to-pulse interferograms, as Fig. 1c shows. According to the space-time duality, the demonstration of spectral information in time domain can be analogized to the spatial Fourier transform based on Fraunhofer’s diffraction [³⁹]. Large group velocity dispersion adds a linear frequency chirp and broadens the pulses. A broadened pulse can have an enlarged temporal width δ,

$$\delta =\left| {\frac{{ - 2\pi c{\beta _2}}}{{{\lambda ^2}}}} \right|L\Delta \lambda$$

Here β₂ is the group velocity dispersion parameter, λ is the central wavelength of the comb pulses, L is the length of dispersive element, and Δλ is the 3-dB spectral bandwidth of the pulse. After DFT, the temporal shape of the broadened pulse is the same as its original spectral shape. Figure 1d shows the calculated result. For a 1550 nm band comb laser, δ linearly increases with |β₂|LΔλ. On the other hand, for avoiding pulse-to-pulse overlap, |β₂|L should be smaller than λ²/(2πcΔλf_r), here f_r is the larger one of the f_r1 and f_r2. Besides, due to the chirping effect, once two stretched pulses overlap, they would interfere with each other in a photodetector. The frequency of their interferometric fringes is given by:

$${f_i}=\frac{\tau }{{2\pi |{\beta _2}|L}}$$

Here τ is the delay of the two pulses. Figure 1e maps the parametric space of the |β₂|L, the τ and the f_i. To satisfy the far-field diffraction condition [⁴⁴], |β₂|L must be much larger than τ₀²/(2π), here τ₀ is the original pulse duration. In experiment, we can control the dispersion parameters to get a proper coefficient for converting τ to f_i. In a nutshell, by using the DFT, we successfully convert the absolute offset measurement of two pulse separations in time domain into a dispersion-related interferometric measurement, which offers a much higher accuracy.

Figure 1f demonstrates our experimental setup. The dual comb source consists of two stabilized mode-locked fiber laser combs. The comb 1 and comb 2 respectively have repetition rates of 24.465 MHz and 24.55 MHz, offering a Δf_r = 85 kHz. They are phase locked on two radio-frequency clocks through two digital feedback loops. After averaging, the minimum uncertainty of the dual comb repetition rates is smaller than 0.25 mHz (10^− 10). More characterizations of the dual comb source are shown in supplementary note S2. The comb 1 is divided into two paths, one works as the probe and the other serves as the reference. The probe light is used for ranging based on the TOF mechanism. The returned probe pulse and the reference pulse (comb 1) are coupled together and launched into a dispersion compensating fiber (DCF) section, while the local pulse (comb 2) is launched into the same DCF section in opposite directions. The DCF provides a β₂ = 110.94 ps²/km. All the pulses are time-stretched in this process. By using 30.39 km DCF (β₂L = 3371.47 ps²), our combs with a 3-dB spectral bandwidth ≈ 6.84 nm (368 fs duration) can be stretched to 18 ns. Finally, the local-probe-reference interferogram is detected by a fast photodetector (25 GHz) and analyzed in a high-speed oscilloscope (16 GHz analog bandwidth).

For a target with a fixed position, the interferometric trace of the synchronized pulse trains (including the returned probe, the reference and the local pulses) is shown in Fig. 2a. In a macroscopic view, it appears similar to the results based on conventional dual-comb ranging method, one can roughly estimate the distance by T_update and the enlarged TOF. Within the TOF duration, we see N = 171. But in a microscopic view, we can see more detailed information, as every pulse has been temporally stretched due to the large dispersion, and interferences occur in the pulse-to-pulse overlapping regions. When zooming the time in, we demonstrate the interferometric details in Fig. 2b. Due to the DFT, one can observe both the ‘local-reference’ fringes plotted in the blue boxes, and the ‘local-probe’ fringes plotted in the orange boxes. These fringes reflect the slight pulse-to-pulse mismatches (τ). Specifically, the fringe frequencies corresponding to τ₁ and τ₂ are f_i,1 = 3.66 GHz and f_i,2 = 3.02 GHz; meanwhile the fringe frequencies corresponding to τ₃ and τ₄ are f_i,3 =1.77 GHz and f_i,4 = 4.91 GHz. Referring the Eq. (3), we can accurately obtain τ₁ = 77.52 ps, τ₂ = 64 ps, τ₃ = 37.48 ps, and τ₄ = 104.04 ps. These values meeting will with the period difference of the comb 1 and the comb 2 (141.52 ps). Therefore, referring Eq. (1), the measured distance is 2.507189 m.

Figure 2c shows the fast Fourier transform spectra of these fringes (f_i1 to f_i4). Thanks to the high stability of the interference, the linewidth of each Fourier peak is < 3 MHz, while the spectrally detectable resolution of the frequency of fringes is < 90 kHz, suggesting a temporal resolution < 0.533 fs for identifying the τ. For ranging, such a performance suggests an in-principle resolution on 240 nm level in single shot measurement. In practice, the system performance is mainly limited by the stability of the dual comb source. More discussion is shown in supplementary note S3. Moreover, the signal-to-noise ratio (SNR) of the lines is commonly higher than 30 dB, suggesting that our measurement can effectively resist the intensity jitter of the pulses. We also note that in our measurement, τ₁ + τ₂ = τ₃ + τ₄ = ΔT is a fixed number. In extreme case, the maximum τ may equal to ΔT (141.52 ps). Referring Eq. (3), the bandwidth of our photodetector & oscilloscope must be higher than 6.684 GHz.

Then we record 1041 repeated ranging results in Fig. 2d. For a single-shot detection, the maximum error is ± 1.3 µm, majorly limited by the instability of the fiber links. Here we also analyze the distribution of the data, which follows a Gaussian distribution. Standard root-mean-square-error (RMSE) of these points is 272.5 nm. Figure 2e plots the statistical Allan deviation of our ranging measurements. For single shot measurement, the typical detection limit is 262 nm. After 1041 averages, the detection limit approaches 2.8 nm. Figure 2f shows the ranging distance. For a single comb with a repetition rate of 24.465 MHz, the NAR is about 6.1 m, which is limited by its pulse period. But after exchanging the role of dual comb, the NAR extends to 1.75 km, determined by the dual comb repetition rate difference Δf_r. These results show that the measured linearity and consistence of the dual comb based Vernier ranging system are good. In supplementary note S3, we compare our ranging system with the conventional TOF method, using the same dual comb light source.

Moreover, the DFT based dual comb ranging can uniquely eliminate the “dead zones”, which has been a widely-recognized challenge in any ranging methods rely on TOF. For a typical TOF measurement, when the probe pulse and the reference pulse are close to each other (the distance approaching 0 or an integer multiple of the L_NAR), one cannot distinguish them due to the Rayleigh criterion. We show the dead zones schematically in Fig. 3a. As a consequence, pulse fitting won’t make sense. To solve this problem, orthogonal polarization multiplexing was applied, but introduced addition complexity [⁴³]. In addition, if the detected pulse has deformation (i.e., not in a perfect sech² or Gaussian shape), it will be more difficult to deterministically fit its peak position.

However, in our scheme, by analyzing the TOF via DFT based interference, we smartly address this problem. Figure 3b plots a case in experiment, here we set the real distance L_R = 2 mm, resulting in a temporal offset of the probe-reference pulses of 13.3 ps. Typically, the small offset between the ‘local-reference’ peak and the ‘local-probe’ peak is difficult to retrieve. But our DFT scheme can distinguish the minor pulse-to-pulse offset clearly, since we can measure the interferometric fringes in the broadened pulses. By zooming the above measured traces in, we demonstrate that the result based on the DFT demonstrates clear interferometric fringes, illustrating a f_i = 628.2 MHz. This verifies L_R = 2 mm accurately.

Specifically, Fig. 3c plots the fast Fourier transform spectra (in log scale) of more cases, where the frequencies of fringes increase when the ranging distance scales from 10 µm to 10 mm. Most of these cases are in the dead zone of a conventional TOF based dual-comb ranging system. In our scheme, the minimum detectable τ is mainly determined by the frequency resolution of the Fourier transform peak (hundreds of nanometers). Therefore, the DFT based dual comb ranging is in-principle ‘dead zone free’. Finally, we show the measured distance versus the real distance in Fig. 3d. The DFT based dual comb ranging enables linear and reliable measurements down to sub µm level.

Finally, we demonstrate two application examples. First, taking advantage of the high accuracy and high consistence of the DFT based dual-comb ranging, we show its capacity for micro-nano morphology. We have prepared a set of three-dimensionally carved English letters (UESTC), as Fig. 4a shows. Size of each letter block is about 2.2 cm × 2.2 cm. Thickness of the substrate is 3 mm. On the substrate, heights of the “U”, “E”, “S”, “T”, “C” are 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, and 0.5 mm respectively. By using collimating lens, we scan our probe beam on the blocks, with spatial scanning step 1 mm. The 2D scanning operation is automatically controlled on an electric displacement table. Figure 4b shows the measured morphologic map (110×24 pixels), with an acquisition time of 0.02 ms for each pixel. In detail, we plot the measured height along the line 12 (marked by the red dashed line) and along raw 55 (marked by the yellow dashed line) in Fig. 4c. The measured heights precisely refer the real height of the letters. In Fig. 4d, we show the statistics of repeated measurements. Here we select 5 points, on the surface of “U”, “E”, “S”, “T”, and “C” respectively. The 5 points’ coordinates are < 7,12>; <30,5>; <55,12>; <78,12>; and < 95,12>. The maximum measurement offset is ± 370 nm, and root-mean-square errors of the 5 selected points are 317 nm, 311 nm, 326 nm, 315 nm, and 331 nm, respectively.

The DFT based dual comb ranging is also applicable for the dynamic measurement of high-speed moving objects, such as a turbofan rotor, as schematically shown in Fig. 4e. In the laboratory, we use this tool to monitor the fast rotation of fan blades for example. The electrical fan has 4 metal blades, its maximum rotation diameter is 10 cm, and the speed of the fan is ≈ 3000 rev/min. Each blade is tilted, with a tilt height ≈ 1 cm. On each blade, there is a small protrusion (≈ 530 µm), marked by the red dashed curve. We focus the laser on the blades at diverse locations (R = 0 mm and 40 mm). For enhancing optical sensitivity, the probe comb is amplified by using a low noise EDFA and collimated by using a lens. Figure 4f plots the measured distance when the probe comb continuously irradiates the fan blades. Determined by the dual comb repetition rate difference, sampling rate is 85 kHz. Within 20 ms, the motion trajectories of the 4 blades are captured. At R = 40 mm, we measure each blade shows a height difference 9.6 mm during rotation. Here the tiny protrusions on the fan surface are also well detectable. In the dynamic measurement, for every rotation period, root mean square for blade 1 to 4 reaches 68 µm, 62 µm, 73 µm and 71 µm respectively. The Allan deviation suggests that when the averaging time is 1.2 ms, the measurement accuracy approaches 170 nm (Fig. 4g). We note that the measurement accuracy of the dynamic ranging is lower than the accuracy when detecting a static target, since the moving blades itself is not so stable.

In addition to in-lab measurements, we also validate the effectiveness of our DFT-based dual comb LIDAR for field applications. For example, this method provides a tool to detect small and slow-moving targets, such as unmanned aerial vehicles (UAVs), which are important targets in both military and civilian applications, but often challenging to measure with traditional radar techniques. In Fig. 5a and 5b, we demonstrate the experimental scenario. We employ a collimator on a tripod head (HY-LW18-01A, horizontal rotation α = 0–360^o, pitch rotation β = 0- 90^o, accuracy 0.1^o) to transmit and receive pulses from the probe comb, and affix a corner prism on the UAV (DJI Air 3) to enhance light reflection. Figure 5c illustrates the measured relative position of a quasi-static target, specifically when the UAV is hovering. In this case, spatial location of the UAV is α = -15^o, β = 45^o, and the LIDAR to target distance is 39.32 m. In Fig. 5d, we plot the continuously collected distance data. It demonstrates that the hovering UAV is rapidly shaking (ms scale, mainly due to the mechanical vibrations) while slowly drifting (second scale, mainly determined by the wind force). Besides measuring a quasi-static target, by scanning the tripod head, we can also trace a dynamically moving target. For instance, in Fig. 5e, we control the UAV linearly flying towards our LIDAR, from the location P1 (coordinate: x = 11.3 m, y = 25.2 m, z = 19.4 m) to P2 (coordinate: x = 7.1 m, y = -4.4 m, z = 2.6 m). In this process, the LIDAR-to-target distance decreases from 33.751 m to 8.748 m. Figure 5f show the measured results. From frame 0 to frame 5, we record the polar coordinate information of the UAV during flight, as Fig. 5g illustrates.

In conclusion, by introducing the dispersive Fourier transform to dual-comb based LIDAR, we demonstrate a physical paradigm that coherent laser ranging can merge the benefits of time-of-flight and in-pulse interferometric methodologies. Different from conventional methods reliant on pulse separation retrieval, the DFT-based dual comb LIDAR scrutinizes Fraunhofer's diffraction with exceptional resolution, shattering the Nyquist sampling constraint while nullifying the trade-off between speed and precision in ranging. This creates a powerful tool for determining absolute distances, boasting high accuracy down to 2.8 nm, extensive non-ambiguity ranges up to 1.7 km, and a unique capability for dead-zone-free measurement. Utilizing this DFT empowered dual-comb ranging scheme, we demonstrate its promising potential in undertaking high-precision morphological measurements and dynamic motion detection. By combining strengths of the Vernier effect of dual comb, time-of-flight techniques, and interferometric analysis, this DFT-based dual-comb ranging approach could pave the way for devising advanced LIDAR systems with broader applications, such as positioning, imaging, and deformation analysis.

Mechanism of the in-fiber dispersive Fourier transform. The large group velocity dispersion (GVD) is provided by two dispersion-compensating fiber modules (Corning PureForm DCM-D-080-04) with a dispersion parameter of D = 87 ps/nm·km and a dispersion slope of S = 0.025 ps/nm²·km. Each module has a group delay dispersion (GDD) of -1322 ps/nm with a total loss of 6.86 dB. Fiber length of each module is 15.2 km. To suppress the ultrafast pulses’ cross-phase modulation (XPM) in the DCFs, we pump signal combs and reference combs from opposite directions through two circulators. Then, two low noise erbium-doped fiber amplifiers (EDFA) with a gain up to ~ 45dB are additionally implemented to provide sufficient signals to detection. After time stretching, the pulse width of a femtosecond pulse (368 fs) with a bandwidth of 6.84 nm is extended to 18 ns. Here, we choose a pulse repetition frequency ≈ 24.55 MHz to ensure that the adjacent pulses do not temporally overlap each other.

Mode locked fiber laser based dual soliton frequency combs. We use dual mode-locked fiber lasers as the signal comb and the reference comb respectively. The fiber resonators are based on hybrid passive mode-locking mechanism (NPR + SESAM). Each mode locked laser comb contains a 980 nm pump laser diode, a section of ~ 2 m long erbium doped fiber (EDF), a semiconductor saturable absorber mirror (SESAM), a section of ~ 6 m long single mode fiber (SMF), a polarization controller (PC) and a polarization dependent-optical integrated component (PD-OIC). The intracavity power is separated by an 80/20 fiber beam splitter, here the 20% power outputs. By adjusting the polarization in cavity, we obtain mode-locked pulse sequence with an average output power of 0.5 mW when the pump power is 10 mW. The total cavity lengths of the signal comb and the reference comb are 8.175 m and 8.147 m respectively, corresponding to the repetition rate of signal pulses and reference pulses 24.465 MHz and 24.55 MHz. Temporal pulses of the dual combs have a single pulse width ~ 368 fs / 416 fs (local comb/ signal comb). The time-bandwidth product (TBP) is 0.316 for local comb and 0.315 for signal comb, which is close to the transformation-limitation, verifying that the initial pulses are chirp-free. We control the geometric length L of the fiber cavity by using a piezoelectric transducer (PZT) with a maximum diameter expansion 0.38 ${\mu }\text{m}$ when the driving voltage is 150 V. By using two servo controllers (Vescent D2-125-IP-230), we locked the repetition rates to a stable RF source.

Experimental setup and device details. Before transmitting the probe pulse into free-space, we used a low noise erbium-doped fiber amplifier (EDFA) to boost the comb power to 300 mW. The collected diffuse reflection power is about − 17 dBm. Before the signal pulses, reference pulses and local pulses are received by the detector, they pass through a polarization controller respectively to ensure that the modulation depth of the interference fringes is large enough. The interference signal is detected with an AC-coupled 25-GHz InGaAs photodetector (Model 1414, Newport) and digitized with a high-speed 20-GHz oscilloscope (DPO72004B, Tektronix) at a sampling rate of 50 GS/s.

Acknowledgments

The authors acknowledge support from the National Key Research and Development Program of China (Grant 2021YFB2800602), the National Natural Science Foundation of China (Grant NSAF U2130106 & NSFC 61975025, and the National Postdoctoral Innovation Talent Support Program of China (BX20220056).

Author contributions

B.C., T.T. and J.D. contributed equally to this work. Y.R. and B.Y. led the group, B.Y. and B.L. led this study. B.C., T.T., J.D. and Z.L. contributed the experimental investigations. B.C., C.W. and H.X. built the laser comb devices. B.C., T.T., X.H. and Z.W. optimized the experimental setup. B.C., T.T. and Z. W. contributed dynamic motion detection. B.C., B.Y., T.T., K.K.Y.W. and B.L. contributed the theoretical analysis. All authors processed and analyzed the results. B.C., B.Y., T.T., B.L. and Y.R. prepared the manuscript.

Competing interests

Authors declare that they have no competing interests.

Data and materials availability

All data are available in the main text or the supplementary materials.

Abbott, B. P. et al. Observation of Gravitational Waves from a Binary Black Hole Merger. Phys. Rev. Lett. 116, 061102 (2016).
Lee, J. et al. Time-of-flight measurement with femtosecond light pulses. Nat. Photonics 4, 716–720 (2010).
Collis, R. T. H. Lidar. Appl. Opt. 9, 1782 (1970).
Berkovic, G. & Shafir, E. Optical methods for distance and displacement measurements. Adv. Opt. Photonics 4, 441 (2012).
Zhang, X. et al. A large-scale microelectromechanical-systems-based silicon photonics LiDAR. Nature 603, 253–258 (2022).
Hänsch, T. W. Nobel Lecture: Passion for precision. Rev. Mod. Phys. 78, 1297–1309 (2006).
Cundiff, S. T. & Ye, J. Colloquium : Femtosecond optical frequency combs. Rev. Mod. Phys. 75, 325–342 (2003).
Fortier, T. & Baumann, E. 20 years of developments in optical frequency comb technology and applications. Commun. Phys. 2, 153 (2019).
Zhang, H. et al. Coherent optical frequency combs: From principles to applications. J. Electron. Sci. Technol. 20, 100157 (2022).
van den Berg, S. A. et al. Many-Wavelength Interferometry with Thousands of Lasers for Absolute Distance Measurement. Phys. Rev. Lett. 108, 183901 (2012).
Riemensberger, J. et al. Massively parallel coherent laser ranging using a soliton microcomb. Nature 581, 164–170 (2020).
Lukashchuk, A. et al. Dual chirped microcomb based parallel ranging at megapixel-line rates. Nat. Commun. 13, 3280 (2022).
Chen, R. et al. Breaking the temporal and frequency congestion of LiDAR by parallel chaos. Nat. Photonics 17, 306–314 (2023).
Lukashchuk, A. et al. Chaotic microcomb inertia-free parallel ranging. APL Photonics 8, (2023).
Kuse, N. & Fermann, M. E. Frequency-modulated comb LIDAR. APL Photonics 4, 106105 (2019).
Papp, S. B. et al. Microresonator frequency comb optical clock. Optica 1, 10 (2014).
Huang, S.-W. et al. A broadband chip-scale optical frequency synthesizer at 2.7 x 10-16 relative uncertainty. Sci. Adv. 2, e1501489–e1501489 (2016).
Bao, C. et al. Quantum diffusion of microcavity solitons. Nat. Phys. 17, 462–466 (2021).
Caldwell, E. D. et al. The time-programmable frequency comb and its use in quantum-limited ranging. Nature 610, 667–673 (2022).
Iwasaki, A. et al. Temporal-offset dual-comb vibrometer with picometer axial precision. APL Photonics 7, 106101 (2022).
Na, Y. et al. Ultrafast, sub-nanometre-precision and multifunctional time-of-flight detection. Nat. Photonics 14, 355–360 (2020).
Chang, L. et al. Integrated optical frequency comb technologies. Nat. Photonics 16, 95–108 (2022).
Sun, Y. et al. Applications of optical microcombs. Adv. Opt. Photonics 15, 86 (2023).
Suh, M. G. & Vahala, K. J. Soliton microcomb range measurement. Science 359, 884–887 (2018).
Yao, B. et al. Gate-tunable frequency combs in graphene–nitride microresonators. Nature 558, 410–414 (2018).
Tan, T. et al. Multispecies and individual gas molecule detection using Stokes solitons in a graphene over-modal microresonator. Nat. Commun. 12, 6716 (2021).
Trocha, P. et al. Ultrafast optical ranging using microresonator soliton frequency combs. Science 359, 887–891 (2018).
Coddington, I. et al. Dual-comb spectroscopy. Optica 3, 414 (2016).
Coddington, I. et al. Rapid and precise absolute distance measurements at long range. Nat. Photonics 3, 351–356 (2009).
Zhu, Z. & Wu, G. Dual-Comb Ranging. Engineering 4, 772–778 (2018).
Yang, Q.-F. et al. Vernier spectrometer using counterpropagating soliton microcombs. Science 363, 965–968 (2019).
Li, B. et al. Bidirectional mode-locked all-normal dispersion fiber laser. Optica 7, 961 (2020).
Yang, Q. F. et al. Counter-propagating solitons in microresonators. Nat. Photonics 11, 560–564 (2017).
Qin, C. et al. Co‐Generation of Orthogonal Soliton Pair in a Monolithic Fiber Resonator with Mechanical Tunability. Laser Photon. Rev. 2200662 (2023) doi:10.1002/lpor.202200662.
Zhang, H. et al. Controllable dual-soliton microcombs using Brillouin excitation. in Conference on Lasers and Electro-Optics JW3B.160 (Optica Publishing Group, 2022). doi:10.1364/CLEO_AT.2022.JW3B.160.
Martin, B. et al. Performance and limitations of dual-comb based ranging systems. Opt. Express 30, 4005 (2022).
Wang, J. et al. Long-distance ranging with high precision using a soliton microcomb. Photonics Res. 8, 1964 (2020).
Ellis, J. L. et al. Scaling up Frequency-Comb-Based Optical Time Transfer to Long Terrestrial Distances. Phys. Rev. Appl. 15, 034002 (2021).
Goda, K. & Jalali, B. Dispersive Fourier transformation for fast continuous single-shot measurements. Nat. Photonics 7, 102–112 (2013).
Mahjoubfar, A. et al. Time stretch and its applications. Nat. Photonics 11, 341–351 (2017).
Li, B. et al. Panoramic-reconstruction temporal imaging for seamless measurements of slowly-evolved femtosecond pulse dynamics. Nat. Commun. 8, 61 (2017).
Wang, B. et al. Vernier frequency division with dual-microresonator solitons. Nat. Commun. 11, 3975 (2020).
Lee, J. et al. Absolute distance measurement by dual-comb interferometry with adjustable synthetic wavelength. Meas. Sci. Technol. 24, 045201 (2013).
Akhmanov, S. et al. Nonstationary nonlinear optical effects and ultrashort light pulse formation. IEEE J. Quantum Electron. 4, 598–605 (1968).

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Dispersive Fourier transform based dual-comb ranging

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Dispersive Fourier transform based dual-comb ranging

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