Ultrafast optical ranging using microresonator soliton frequency combs

Abstract: Light detection and ranging (LIDAR) is critical to many fields in science and industry. Over the last decade, optical frequency combs were shown to offer unique advantages in optical ranging, in particular when it comes to fast distance acquisition with high accuracy. However, current comb-based concepts are not suited for emerging high-volume applications such as drone navigation or autonomous driving. These applications critically rely on LIDAR systems that are not only accurate and fast, but also compact, robust, and amenable to cost-efficient mass-production. Here we show that integrated dissipative Kerr-soliton (DKS) comb sources provide a route to chip-scale LIDAR systems that combine sub-wavelength accuracy and unprecedented acquisition speed with the opportunity to exploit advanced photonic integration concepts for wafer-scale mass production. In our experiments, we use a pair of free-running DKS combs, each providing more than 100 carriers for massively parallel synthetic-wavelength interferometry. We demonstrate dual-comb distance measurements with record-low Allan deviations down to 12 nm at averaging times of 14 $\mu$s as well as ultrafast ranging at unprecedented measurement rates of up to 100 MHz. We prove the viability of our technique by sampling the naturally scattering surface of air-gun projectiles flying at 150 m/s (Mach 0.47). Combining integrated dual-comb LIDAR engines with chip-scale nanophotonic phased arrays, the approach could allow widespread use of compact ultrafast ranging systems in emerging mass applications.

• The paper introduces a free-running dual-comb method using dissipative Kerr solitons that enables chip-scale LIDAR with over 100 carriers and 100 MHz measurement rates.
• The paper achieves ultrahigh precision, recording Allan deviations as low as 12 nm over 14 µs and lateral resolutions below 2 µm at speeds exceeding 150 m/s.
• The paper’s innovative integration of DKS combs paves the way for scalable, robust optical ranging systems in high-volume applications like autonomous vehicles and advanced manufacturing.

Ultrafast Optical Ranging Using Microresonator Soliton Frequency Combs

This paper presents advancements in Light Detection and Ranging (LIDAR) technology through the use of microresonator soliton frequency combs, aiming for applications that demand high precision and ultrafast data acquisition. The primary focus of this research is to innovate a method suitable for chip-scale LIDAR systems that can blend with advanced photonic integration for mass production, offering substantial improvements in speed and accuracy over existing technologies.

Key Contributions

The research introduces the use of dissipative Kerr soliton (DKS) combs in dual-frequency configurations to achieve unprecedented measurement speeds and precision. This technique employs a pair of free-running DKS combs, each facilitating over 100 carriers, thereby enabling massively parallel synthetic-wavelength interferometry. The novel approach records Allan deviations as low as 12 nm over an averaging time of 14 µs and supports measurement rates that soar to 100 MHz. This marks a significant throughput increase, surpassing previous methodologies by more than an order of magnitude.

In contrast to earlier dual-comb approaches, which often relied on phase-locked comb generators, the authors demonstrate the viability of free-running comb configurations, simplifying the implementation and enhancing robustness for integrated applications. The paper substantiates these claims through practical experiments, including capturing the surface profile of air-gun projectiles in motion, achieving lateral spatial resolutions of under 2 µm at object speeds exceeding 150 m/s.

Implications of the Research

Practically, this research provides a pathway for the development of highly compact LIDAR systems that maintain superior performance metrics, opening avenues for their proliferation in high-volume applications such as autonomous vehicle navigation and advanced manufacturing processes. The use of integrated DKS-based dual-comb LIDAR systems could yield transformative impacts across various domains where high-precision and rapid acquisition speeds are critical.

Theoretically, the integration of DKS combs and dual-comb techniques offers insights into the potential leverage of large-scale nanophotonic phased arrays, promising enhancements in ultra-compact system design and beam steering capabilities. Moreover, the research might stimulate further exploration into novel photonic integration strategies that prioritize efficiency and scalability.

Future Prospects

While this paper sets the groundwork for ultrafast LIDAR systems, several potential research directions emerge. Future work could refine the fabrication processes to enhance the stability and yield of photonic integrated circuits featuring DKS combs. Additionally, exploring different materials and waveguide configurations could further improve the performance and adaptability of these systems.

For the LIDAR technology itself, integration with other sensing modalities and the exploration of broader application domains seem promising. Continued advancements in hardware, along with robust data processing algorithms, could expand the usage scenarios for optical ranging technologies significantly.

In conclusion, this paper presents a pivotal step towards harnessing DKS frequency combs for practical LIDAR applications, marrying high accuracy with unprecedented speed on a compact scale, ultimately driving forward the boundaries of what is achievable in optical ranging technologies.