The optical lens market is large and expects to see ongoing significant growth over the coming years, with a projected compound annual growth rate (CAGR) of 6.87 worldwide by 2027. One of the key areas of market expansion is Light Detection and Ranging (LiDAR) technology. For many applications, LiDAR devices provide benefits compared to other sensing technologies, such as RF-based short to long range radar, ultrasonic sensors, and infrared sensors. The increasing availability of components designed for LiDAR technology is enabling broader capabilities and more competitive pricing, lending it to a variety of applications that require high performance in a compact package with high reliability and relatively low cost.
LiDAR uses pulsed light waves emitted by the sensor system and the light’s time of flight to map its surroundings into 3D images. This is unlike typical 2D imaging which provides a view of the scene based on the variation of reflected (visible to shortwave infrared [SWIR] or emitted thermal infrared) light over the azimuth and elevation field of view of the sensor, but with no sense of depth. While similar in principle to radar, the shorter wavelengths used by LiDAR allow the system components to be smaller than those used for RF radar and for the resolution with respect to system size, weight, and power consumption (SWaP) to be higher, especially at ranges out to 100 m.
Lower-power, shorter-range LiDAR systems typically use near-infrared (NIR) light between 800 nm and 1000 nm and can leverage a wide variety of existing laser light sources and silicon-based sensors. Longer-range and fog/smoke-penetrating LiDAR use higher-intensity SWIR light sources and typically InGaAs sensors to achieve greater performance under even lower-visibility conditions. The light from both types is invisible to the human eye, and the use of SWIR light allows higher-intensity light sources to be used for greater range while still being eye-safe to people near the system.
Two of the highest-growth areas for LiDAR components are in the military field and in the automotive industry. The following provides an overview of how LiDAR technology is being utilized in these areas.
LiDAR technology for military applications may include:
- Tactical mapping from unmanned aerial, terrestrial, or aquatic vehicles. The compact and relatively energy-efficient nature of LiDAR in shorter-range applications allow small autonomous platforms, like drones, to create 3D maps of the battlefield. This can be used to locate threats or even to create accurate 3D representations for operational training using realistic battle simulators.
- Low-flying military aircraft, particularly helicopters, are at collision risk from hard-to-see electrical power lines and towers. Additionally, safe landing of helicopters requires assurances of the flatness of the terrain directly underneath the aircraft. LiDAR addresses both by enabling detection and tracking of small objects like wires, and high-fidelity 3D mapping of terrain, even through dust that may be kicked up during landing.
- Engineering and planning with topographic LiDAR applications which can be used to derive surface models for use in many applications, such as forestry, hydrology, geomorphology, urban planning, landscape ecology, coastal engineering, survey assessments, and volumetric calculations.
Driver assistance and autonomous navigation is propelling demand for LiDAR technology in the automotive market:
- Advanced driver assistance systems (ADAS) based on LiDAR enable continuous, fast, and high-fidelity 3D mapping of the surroundings of a moving vehicle under daytime and nighttime conditions. This allows the vehicle’s on-board control system to track how quickly objects are moving towards the vehicle, or it towards them, and provide driver warnings or interventions (e.g., braking) to avoid collisions.
- The mainstream market for autonomous vehicles is an area of high interest for many vehicle manufacturers; in addition, it represents a key area of application for LiDAR technology.
- From rooftop sensors to those embedded in headlamps, there are many different configurations for LiDAR and component lenses. As technology progresses, it is expected that this market will grow significantly, supporting the potential for enhanced vision capabilities and improved driver safety.
Optical lenses in LiDAR systems.
LiDAR systems comprise light transmitter and receiver assemblies that need to have the best performance for SWaP and cost, based on the specifics of the LiDAR approach. Common to all types of LiDAR is the need for efficient and accurate projection of the illumination to the scene by the transmitter optics. Also common to all LiDAR systems is the need to maximize light collection while ensuring accurate imaging onto the sensor by the receiver optics. Optical systems for LiDAR tend to require low f/number, high transmission, and moderate resolution.
Today’s available commercial off-the-shelf (COTS) lenses are typically slower (i.e. high f/number), have more complex lens designs supporting high resolution, have smaller image planes than are needed by many LiDAR sensor and source technologies, and are designed for visible light as opposed to NIR and SWIR wavelengths. This can make it a challenge to identify a COTS source of optics for both the development and production phases of LiDAR system manufacture.
Fortunately, there are lens designs suited to high-efficiency and compact optics for LiDAR, and manufacturing approaches that can bridge the gap between low-volume development and cost-effective, high-volume production. Optics combining spherical glass and plastic aspheric components in low-volume development, merging into an environmentally robust all-glass aspheric design for high volume, has been made possible by the maturing of the diamond turning and glass molding technologies over the past 10-20 years.
The military and automotive industries are just two of the key markets where LiDAR systems are poised to expand both revenue and the capabilities available to those organizations who use them. Ross Optical provides a full complement of optical lenses to meet the specifications of your LiDAR project. Contact our engineering team today to learn more.
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