FMCW LiDAR sensing technology finds utility in the automotive, robotics and industrial verticals
Key Highlights
- FMCW LiDAR measures distance and velocity by analyzing frequency shifts, providing higher resolution and longer range than ToF systems.
- It is less susceptible to interference from sunlight and other light sources, ensuring more reliable measurements in various environments.
- The technology can directly measure object speed using the Doppler effect, enabling better obstacle detection and navigation.
- Partnerships between vendors like LightIC and Enablence are accelerating FMCW integration into commercial products, with production ramping up.
- Integration of photonic circuits, especially silicon photonics and PLCs, is key to making FMCW LiDAR more compact, cost-effective, and scalable.
What is LiDAR?
LiDAR is a laser imaging detection and ranging system that uses a laser, a form of light, to measure the variable distances from Earth. This technology is widely used to measure various areas relatively quickly with greater accuracy than manual labor and to create three-dimensional images. There are three main types of LiDAR: terrestrial, aerial, and mobile. Terrestrial LiDAR is also known as Terrestrial Laser Scanning (TLS) or topographic LiDAR.
Frequency-Modulated Continuous-Wave (FMCW) Light Detection and Ranging (LiDAR) may not be new in any respect, but their role as fiber optic sensors continues to find new commercial adoption.
LiDAR systems use optics technology to shape and direct laser beams to the field of view, attaining exceptionally reliable measurements critical for advanced sensing applications in automotive, industrial automation, and robotics.
Time-of-flight (ToF) and Frequency Modulated Continuous Wave (FMCW) are two main types of LiDAR technology, each with its proponents.
ToF measures distance by timing the round trip of a light pulse, while FMCW measures distance by analyzing the frequency shift of a continuous wave.
FMCW LiDAR technology measures distance and velocity by analyzing the frequency shift of a continuously emitted, frequency-modulated laser beam, offering higher resolution and velocity measurement capabilities. Instead of emitting short pulses, FMCW LiDAR continuously emits a laser beam whose frequency is modulated.
Todd Haugen, CEO of Enablence, said optical sensing has continued to evolve over the past few decades; however, these developments have primarily been of a lower-tech nature. “The advent of warehouse robotics and automotive LiDAR has made big advancements over the past five years," he said.
What is FMCW LiDAR?
Frequency Modulated Continuous Wave (FMCW) LiDAR is a type of light detection and ranging (LiDAR) technology that uses a continuously emitted laser beam with a changing frequency to measure distances and velocities with high precision. Advocates of FMCW LiDAR argue that it has an advantage over other methods, such as Time-of-Flight (ToF) LiDAR. While ToF LiDAR measures the time it takes for a light pulse to travel to an object and return, FMCW LiDAR analyzes the frequency shift of light waves reflected from the object. This enables it not only to determine distance but also to measure the velocity of objects, making it a good fit for applications such as autonomous vehicles and robotics.
FMCW versus ToF LiDAR
Proponents of FMCW, which employs frequency modulation principles, argue that the technology offers greater accuracy, robustness, and long-term reliability compared to competing Time-of-Flight (ToF) LiDAR systems.
While ToF LiDAR needs to estimate velocity from changes in position, FMCW can directly measure an object's speed using the Doppler effect. Because of its coherent detection, FMCW LiDAR is less susceptible to light interference (such as sunlight). FMCW LiDAR signals also extend to longer ranges than ToF LiDAR.
Optical transceivers are key components in LiDAR systems. When the laser beam reflects off an object, the reflected light's frequency shifts due to the object's motion (the Doppler effect) and its distance. The FMCW LiDAR system then compares the frequency of the reflected light with the frequency of the emitted light to determine the object's distance and velocity. LightIC's FMCW LiDAR products enable the market's highest-precision distance and velocity measurements.
Jin Sun, CEO of LightIC, noted that FMCW has evolved since the 1950s.
“FMCW has been around for several decades and is a close relative of radar technology,” he said. “When it comes to automotive and other sensing applications, including radar, it is almost exclusively FMCW.”
He added that LiDAR, a technology like radar that operates at a higher frequency, also began with ToF.
“We decided to work on FMCW LiDAR because we saw this turning point from traditional Time-of-Flight to FMCW,” Sun said.
FMCW LiDAR technology measures distance and velocity by analyzing the frequency shift of a continuously emitted, frequency-modulated laser beam, offering higher resolution and velocity measurement capabilities. Instead of emitting short pulses, FMCW LiDAR continuously emits a laser beam whose frequency is modulated.
Unlike ToF LiDAR, which requires estimating velocity from changes in position, FMCW can directly measure an object's speed using the Doppler effect. Because of its coherent detection, FMCW LiDAR is also less susceptible to light interference (such as sunlight) compared to ToF LiDAR.
Haugen said that there will be an ongoing migration from ToF to FMCW in industries like automotive.
“In the automotive industry, the module cost when you talk about FMCW is higher than ToF, but on the backend, ToF’s cost is higher than FMCW,” he said. “As the software portion gets more tightly integrated with the rest of the vehicle and the value of the signal comes from FMCW, you will see this shift accelerate.”
While the challenge with FMCW is mainly due to ToF having had a head start, Haugen added that he foresees the technology's role in various automotive segments, such as long-haul trucking. It could also impact ADAS (Advanced Driver-Assistance Systems), which assist drivers with multiple aspects of driving, including safety, convenience, and comfort.
“The problem today is that ToF is an established market with various vendors developing its products and software,” Haugen said. “Like anything, when transitioning from the first to the second generation, a certain amount of maturity must happen throughout the ecosystem.”
Wide range of uses
The emergence of FMCW LiDAR continues to find new uses. FMCW LiDAR sensors can meet the growing demand for a wide range of advanced industrial applications where high precision is critical to ensuring advanced automation.
Automotive, robotics, and industrial automation require the most precise navigation and obstacle detection capabilities.
While FMCW is new to LiDAR, LightIC is seeing the migration from ToF to FMCW. Today, the majority of the automotive sensors are based on ToF technology.
Enhancing operational reliability in dynamic environments is critical in robotics. Most importantly, providing real-time, accurate velocity awareness can be lifesaving in the automotive industry.
“The advantage of FMCW is that it can detect not only the distance of an object, but also the velocity of an object,” Sun said. “You will also know where the object is right now and where it will be in the next second, which is a big advantage.”
While FMCW initially found an application in aeronautics due to its precise nature, Haugen said that it will continue to find relevance in the automotive industry. “When driving around town, a driver does not need high-level precision, but when you get on the highway driving at faster speeds, it becomes paramount.
Sun said that FMCW can more accurately identify objects surrounding a vehicle, such as pedestrians and motorcycles, as a car travels on a road or highway.
“With FMCW, a sensor only needs three points to identify an object, unlike Time-of-Flight (ToF) technology, which needs 30 or 40 points,” he said. “With FMCW LiDAR, you can reduce the resolution of the LiDAR and achieve the same or even better results.”
Partnerships emerge
Being an emerging technology application, partnerships between vendors continue to surface for FMCW.
Enablence Technologies, a provider of planar lightwave (PLC) optical chips and subsystems, has established a partnership with LightIC to supply its PLC optical chips in its FMCW LiDAR sensor products.
Haugen said its partnership with LightIC represents an intersection point.
“It uses an automotive style of LiDAR in a warehouse application that drives exceptional levels of precision,” Haugen said. “What that does is in a pick and pull environment, which is what the robots are being used for, there are fewer drops.”
The adoption of LightIC's next-generation FMCW LiDAR products is rising, as their long-range, direct velocity detection, precision, and interference immunity help accelerate advances in automotive, robotics, and industrial automation.
“Integration with silicon photonics will bring everything down to a chip level,” Sun said. “We can reduce the complexity of otherwise disparate optical systems, which is what we have done with Enablence.”
Already, LightIC is making progress in getting its FMCW LiDAR products to market through its partnership with Enablence.
Since starting in the fourth quarter of 2024, LightIC has shipped 300 FMCW LiDAR units for industrial applications.
Sun said, “We plan to ship around 3,000 units this year.”
Haugen said the Enablence and LightIC partnership will continue to evolve. “If you look at our R&D cycle for the first product, our teams work closely together almost like one company,” he said. “That kind of partnership advances these new capabilities, and we’ll continue working with LightIC on multiple products and scenarios.”
But what’s key is well-defined timelines, particularly as LightIC faces a market surrounded by other aggressive players. “Fast turnaround time is critical for product development because with the automotive LiDAR product, we have fierce competition from Chinese companies that move fast,” Sun said. “By working with Enablence, we brought a new product to market in less than two years.”
Sun added that LightIC “could see more products, not just industrial but also automotive, as we continue our collaboration to get a faster turnaround time.”
LiDAR growth ahead
The LiDAR market size has grown rapidly in recent years. According to the Business Research Company, the market will increase from $2.54 billion in 2024 to $3.03 billion in 2025 at a compound annual growth rate (CAGR) of 19.1%. The growth in the historic period can be attributed to automotive safety regulations, increasing demand for LiDAR in applications such as topographic mapping, agriculture and forestry, growth in military and defense, smart cities and infrastructure. The LiDAR market is expected to grow rapidly in the next few years. It will grow to $6.08 billion in 2029 at a compound annual growth rate (CAGR) of 19.0%.
Making FMCW mainstream
To make FMCW a mainstream technology, a key element for vendors is integration.
LightIC maintains that the best approach for conducting integration is to utilize planar lightwave circuits (PLCs). PLCs utilize semiconductor processes, including photolithography, etching, and deposition, to create optical paths on substrates, thereby enabling the propagation of optical signals.
PLC technology offers a low-signal loss advantage, which enables long delay lines critical for maintaining FMCW laser accuracy. By integrating LightIC's silicon photonic FMCW technology with Enablence's PLC optical chips, the two companies claim that customers gain optimal cost and performance.
Enablence's PLCs deliver a set of integrated optics chips. Through its custom design services, Enablence provides fabrication services for applications including astronomy, data centers, LiDAR, industrial sensors, and virtual reality.
“The biggest enabler for FMCW technology to make it mainstream is how you do integration,” Sun said. “The natural solution is to use Photonic Integrated Circuits (PICs), including silicon photonics and PLC, which enables the technology.”
One of the several benefits of working with Enablence is that it enhances accuracy and range due to the low loss of PLCs. For its LiDAR platform, at a distance of 100 meters, it can achieve a resolution of 1.5 millimeters.
But this is not just a science experiment. Already, LightIC is in production mode.
Sun said precision will be key as AI moves forward with its need to gather data continuously.
“When you provide these industrial sensors to warehouses and robotics, where you need high accuracy to locate objects precisely,” Sun said. “There are other applications because we are in this AI world. So, for AI to work, they need a lot of data for training, and the way to get the physical data is from optical sensors.”
He added that the need for optical sensors will continue to rise. “We need more and more optical sensors with higher precision for many applications,” Sun said. “It’s a big market for industrial automation and the automotive industry.”
Despite its potential benefits, the main challenge FMCW faces is that ToF has the first mover advantage.
“The problem proponents of FMCW are having today is that ToF is an established market with various vendors developing software and electronics for it already,” Haugen said. “When you are making a transition from generation one to generation two, there’s a maturity that has to happen throughout the ecosystem.”
However, FMCW has potential applications in areas such as government initiatives, including Advanced Driver Assistance Systems (ADAS), and long-haul trucking. ADAS are electronic systems designed to assist drivers with various driving tasks, enhancing safety and comfort. They utilize sensors and cameras to detect potential hazards and provide alerts or even intervene to prevent accidents.
“ADAS systems need so much warning for vehicles, and that’s where we will see the first big push in FMCW,” Haugen said. “As soon as that happens, it starts the whole process with building the ecosystem, and it becomes a de facto standard.”
Sun agreed and added that FMCW can provide various benefits to the automotive industry with a more efficient view of objects. “FMCW can provide low-latency detection of an object,” he said. “For Time of Flight to detect where an object is moving to you, it probably needs a few frames, but with FMCW, it can be done on the first frame and from a longer distance.”
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Sean Buckley
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