in a full system. Along these lines, there is remarkable progress on realization of microcomb
systems (20). Moreover, a waveguide-integrated
structure comparable in performance to that used
in this work has recently been demonstrated (34).
Finally, we note other soliton microcomb range
measurement work (35) that was reported while
we were preparing this manuscript.
REFERENCES AND NOTES
1. Y. Salvadé, N. Schuhler, S. Lévêque, S. Le Floch, Appl. Opt. 47,
2. E. Baumann et al., Opt. Lett. 38, 2026–2028 (2013).
3. I. Coddington, W. Swann, L. Nenadovic, N. Newbury, Nat.
Photonics 3, 351–356 (2009).
4. S.-J. Lee, B. Widiyatmoko, M. Kourogi, M. Ohtsu, Jpn. J. Appl.
Phys. 40, L878–L880 (2001).
5. P. Del’Haye et al., Nature 450, 1214–1217 (2007).
6. T. J. Kippenberg, R. Holzwarth, S. A. Diddams, Science 332,
7. I. S. Grudinin, N. Yu, L. Maleki, Opt. Lett. 34, 878–880
8. S. B. Papp, S. A. Diddams, Phys. Rev. A 84, 053833
9. Y. Okawachi et al., Opt. Lett. 36, 3398–3400 (2011).
10. J. Li, H. Lee, T. Chen, K. J. Vahala, Phys. Rev. Lett. 109, 233901
11. B. Hausmann, I. Bulu, V. Venkataraman, P. Deotare, M. Lončar,
Nat. Photonics 8, 369–374 (2014).
12. L. Razzari et al., Nat. Photonics 4, 41–45 (2010).
13. F. Ferdous et al., Nat. Photonics 5, 770–776 (2011).
14. H. Jung, C. Xiong, K. Y. Fong, X. Zhang, H. X. Tang, Opt. Lett.
38, 2810–2813 (2013).
15. T. Herr et al., Nat. Photonics 8, 145–152 (2014).
16. X. Yi, Q.-F. Yang, K. Y. Yang, M.-G. Suh, K. Vahala, Optica 2,
17. V. Brasch et al., Science 351, 357–360 (2016).
18. P.-H. Wang et al., Opt. Express 24, 10890–10897 (2016).
19. C. Joshi et al., Opt. Lett. 41, 2565–2568 (2016).
20. D. T. Spencer et al., arXiv:1708.05228 (2017).
21. P. Marin-Palomo et al., Nature 546, 274–279 (2017).
22. M.-G. Suh, Q.-F. Yang, K. Y. Yang, X. Yi, K. J. Vahala, Science
354, 600–603 (2016).
23. A. Dutt et al., arXiv:1611.07673 (2016).
24. N. G. Pavlov et al., Opt. Lett. 42, 514–517 (2017).
25. Q.-F. Yang, X. Yi, K. Y. Yang, K. Vahala, Nat. Photonics 11,
26. H. Lee et al., Nat. Photonics 6, 369–373 (2012).
27. X. Yi, Q.-F. Yang, K. Y. Yang, K. Vahala, Opt. Lett. 41,
28. Q.-T. Cao et al., Phys. Rev. Lett. 118, 033901 (2017).
29. L. Del Bino, J. M. Silver, S. L. Stebbings, P. Del’Haye, Sci. Rep.
7, 43142 (2017).
30. See supplementary materials.
31. T.-A. Liu, N. R. Newbury, I. Coddington, Opt. Express 19,
32. J. Lee, Y.-J. Kim, K. Lee, S. Lee, S.-W. Kim, Nat. Photonics 4,
33. N. Bobroff, Meas. Sci. Technol. 4, 907–926 (1993).
34. K. Y. Yang et al., arXiv:1702.05076 (2017).
35. P. Trocha et al., arXiv:1707.05969 (2017).
We thank N. Newbury, X. Yi, and Q. Yang for helpful
discussions and feedback on this manuscript. Supported
by the Defense Advanced Research Projects Agency under
the SCOUT (contract no. W911NF-16-1-0548) program,
the Air Force Office of Scientific Research, and the Kavli
26 June 2017; accepted 11 January 2018
Ultrafast optical ranging
using microresonator soliton
P. Trocha,1 M. Karpov,2 D. Ganin,1 M. H. P. Pfeiffer,2 A. Kordts,2 S. Wolf,1
J. Krockenberger,1 P. Marin-Palomo,1 C. Weimann,1† S. Randel,1,3 W. Freude,1,3
T. J. Kippenberg,2‡ C. Koos1,3‡
Light detection and ranging is widely used in science and industry. Over the past
decade, optical frequency combs were shown to offer advantages in optical ranging,
enabling fast distance acquisition with high accuracy. Driven by emerging high-volume
applications such as industrial sensing, drone navigation, or autonomous driving,
there is now a growing demand for compact ranging systems. Here, we show that
soliton Kerr comb generation in integrated silicon nitride microresonators provides
a route to high-performance chip-scale ranging systems. We demonstrate dual-comb
distance measurements with Allan deviations down to 12 nanometers at averaging
times of 13 microseconds along with ultrafast ranging at acquisition rates of
100 megahertz, allowing for in-flight sampling of gun projectiles moving at 150 meters
per second. Combining integrated soliton-comb ranging systems with chip-scale
nanophotonic phased arrays could enable compact ultrafast ranging systems for emerging
Laser-based light detection and ranging (LIDAR) is a key technology in industrial and scientific metrology, offering high- precision, long-range, and fast acquisition (1, 2). LIDAR systems have found their way
into a wide variety of applications, comprising,
for example, industrial process monitoring, auton-
omous driving, satellite formation flying, or
drone navigation. When it comes to fast and ac-
curate ranging over extended distances, optical
frequency combs (3) have been demonstrated
to exhibit characteristic advantages, exploiting
time-of-flight (TOF) schemes (4), interferometric
approaches (5), or combinations thereof (6). In
early experiments (4), mode-locked fiber lasers
were used for TOF ranging, thereby primarily
exploiting the stability of the repetition rate. Re-
garding interferometric schemes, optical frequen-
cy combs were exploited to stabilize the frequency
interval between continuous-wave (CW) lasers
used in synthetic-wavelength interferometry (5, 7).
Dual-comb schemes, which rely on multihetero-
dyne detection by coherent superposition of a
pair of slightly detuned frequency combs (8), al-
low combining of TOF measurements with optical
interferometry, thereby simultaneously exploit-
ing the radio-frequency coherence of the pulse
train and the optical coherence of the individ-
ual comb tones (6). More recently, comb-based
schemes have been demonstrated as a viable
path to high-speed sampling with acquisition
times down to 500 ns (9).
However, besides accuracy and acquisition
speed, footprint is becoming increasingly important for LIDAR systems. On the technology
side, recent advances in photonic integration
show that large-scale nanophotonic phased arrays (10, 11) open a promising path toward ultra-compact systems for rapid high-resolution beam
steering. To harness the full potential of these
approaches, the optical phased arrays need to
be complemented by LIDAR engines that combine high precision with ultrafast acquisition and
that are amenable to chip-scale integration. Existing dual-comb LIDAR concepts cannot fulfill these requirements because they rely either
on cavity-stabilized mode-locked fiber lasers (6)
or on spectral broadening of initially narrow-band seed combs (9), which typically require
delicate fiber-based dispersion management
schemes, usually in combination with intermediate amplifiers.
Here, we show that dissipative Kerr soliton
(DKS) states (12, 13) in microresonator-based
optical frequency combs (14, 15) provide a route
to integrated LIDAR systems that combine subwavelength accuracy and unprecedented acquisition speed with scalable fabrication, robust
implementation, and compact form factors. DKSs
are solutions of a driven, damped, and detuned
nonlinear Schrödinger equation, often referred
to as a Lugiato-Lefever equation (16). Such ultrashort temporal solitons can circulate continuously in the cavity, relying on a double balance
of dispersion and nonlinearity as well as parametric gain and cavity loss (13). In the frequency
1Institute of Photonics and Quantum Electronics (IPQ),
Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe,
Germany. 2Laboratory of Photonics and Quantum
Measurements (LPQM), École Polytechnique Fédérale de
Lausanne (EPFL), CH-1015 Lausanne, Switzerland. 3Institute
of Microstructure Technology (IMT), Karlsruhe Institute of
Technology, 76131 Karlsruhe, Germany.
*These authors contributed equally to this work. †Present address:
Corporate Research and Technology, Carl Zeiss AG, Oberkochen,
Germany. ‡Corresponding author. Email: tobias.kippenberg@
epfl.ch (T.J.K.); firstname.lastname@example.org (C.K.)