Blickfeld solid-state technology – LiDAR for the mass market
Until now, LiDAR systems were lacking in efficiency and robustness and, above all, were too expensive for mass use in the automotive industry. The Blickfeld technology focuses on MEMS silicon components and highly automated production, thus paving the way for autonomous vehicles.
As a means of measuring emissions in atmospheric research or for remote sensing in archaeology, LiDAR technology has been used successfully in various areas for decades. The problem with many of today’s LiDAR systems is that the mechanics used are sensitive to harsh environmental conditions such as vibrations, shocks, heat and cold. More importantly, LiDAR sensors are not available in large quantities or at affordable prices today. This is a major problem for the automotive industry, which is desperately looking for high-performance LiDAR systems with a robust and production-scalable design. This technology is needed for the autonomous cars of tomorrow. Experts expect several such robust LiDAR sensors to be installed per car in the future.
Blickfeld’s goal is to develop LiDAR products that are powerful and robust enough for use in vehicles and that can be manufactured in large quantities without difficulty. To achieve this, Blickfeld starts with the beam deflection unit. Classical mechanically rotating concepts are complex in design and production, which translates into large dimensions and a high price. Other technologies and designs, such as optical phased array and flash LiDAR, have the potential to be much smaller in size and cheaper in production, but are still at the very beginning of their development or have system-related disadvantages such as a very limited range. On the other hand, MEMS mirror-based LiDAR sensors are a promising solution. Their silicon construction is already well advanced and successfully used in many applications. In addition, MEMS technology does not require rotating components and is therefore much more robust and durable than mechanical LiDAR systems. However, currently available MEMS mirrors for deflecting laser beams have small mirror sizes and small deflection angles. Their performance in terms of range and covered field of view is therefore limited.
The Blickfeld MEMS technology is specifically optimized for a maximum range and a large field of view and therefore has none of the limitations mentioned. With generous dimensions of more than ten millimetres in mirror diameter, the Blickfeld MEMS mirror can direct a high proportion of incident light onto the photodetector. Thus, the Blickfeld LiDAR reliably detects objects with a low reflection at a distance of more than 150 metres. Moreover, the MEMS mirror also achieves a large deflection, which enables a scanning angle of 120 x 30 degrees and thus a wide field of view. Another advantage of the technology is that the light emitted by the laser and deflected onto the scene by the MEMS mirror is guided back to the detector along an optically almost identical path after being reflected by the objects in the field. This so-called coaxial construction results in a spatial filtering effect, which in turn minimizes background light, e.g. from the sun or other LIDARs. In this manner, the Blickfeld technology achieves a very high signal-to-noise ratio, which benefits the range.
The Blickfeld MEMS mirrors are manufactured using low-cost photolithographic production techniques that enable maximum precision with extreme scalability: A standard silicon wafer with a diameter of 200 millimetres is turned into hundreds of highly automated MEMS components simultaneously. The standard method, which has been tried and tested in the semiconductor industry for decades, makes the Blickfeld technology perfectly suited for the mass market. Finally, the simple, robust design of the Blickfeld MEMS mirror and the high functionality significantly reduce the complexity of the overall LiDAR design. In addition to various special laser and detector units available on the market, Blickfeld can also work with reliable and proven standard optical components. All these advantages are now combined in the first series product: the Blickfeld Cube – an integrated, high-resolution 3D-LiDAR module.
For the Cube, Blickfeld has set itself the goal of optimizing performance, reliability and scalability. Therefore, Blickfeld focuses on laser diodes with a wavelength of 905 nanometres as emitters and silicon photomultipliers (SiPMs) as detectors that can detect individual photons. These components have been extensively tested, have been used millions of times in various devices for many years and have proven to be extremely reliable. In order to meet the high quality and quantity requirements, the Cube is produced on a highly automated production line. The 3D-LiDAR module is designed and optimized in such a way that tools similar to those used in the highly standardized production of vehicle cameras can be used. When completed, each line will have a production capacity of more than 100,000 cube units per year. With the Cube, the first Blickfeld product will be commercially available from the middle of this year.