Lidar is ready to go, and the industrial path is gradually clear
Lidar is about to be mass produced. The rotating mirror / MEMS scheme is used as the main radar for long-distance detection. The product form of flash as blinding radar is expected to be maintained. In the long term, the pure solid-state OPA + FMCW is expected to become the end of the lidar industry. Lidar is about to enter the eve of large-scale mass production. At present, the rotating mirror and MEMS scheme have relatively balanced performance indicators, mature supply chain system and relatively controllable cost, and are easier to meet the requirements of vehicle regulations. They have become two major ways that can be popularized on a large scale in the medium and short term. The industry chain company is expected to usher in opportunities. Due to the characteristics of limited short-term detection distance, low cost and pure solid state, flash scheme is expected to be used as a blinding radar for a long time. In the long term, FMCW + OPA mode is expected to become the end of the lidar industry with its performance beyond the limits of existing schemes, low cost and high stability under pure solid-state structure.
Ranging mode: TOF is the mainstream at present, and FMCW has broad prospects
TOF ranging method is simple, easy to use and low cost. It is the mainstream ranging method at present. FMCW ranging method has excellent performance, but it is difficult to achieve in the short term due to high technical barriers. At present, players in the market mainly use TOF ranging. FMCW has low transmission power, high signal-to-noise ratio and strong anti-interference ability. The product is easier to chip and can obtain the speed information of the object. However, the modulator and laser used for FMCW are not mature, and the integrated silicon optical process has not yet reached the level of mass production. At present, it is difficult to produce and use on a large scale.
Scanning mode: MEMS and rotating mirror have excellent performance and are relatively easy to pass the vehicle gauge, which has become the mainstream at present
There are many beam scanning methods. At present, rotating mirror and MEMS will become the first choice for mass production. In the long term, pure solid-state OPA and flash are expected to become the end of lidar. The space for mechanical cost reduction is limited, the rotating structure is difficult to meet the requirements of vehicle regulations, and it is difficult to get on the vehicle in mass production. The rotating mirror type is similar to the miniaturized mechanical scanning. It has excellent performance and is relatively easy to pass the vehicle gauge, but there are still mechanical moving parts and the cost reduction space is limited. The MEMS scheme has a variety of deployment modes. Overall, the performance can meet the requirements and it is relatively easy to pass the vehicle gauge, but the stability of MEMS mirror needs to be improved. Flash scheme is pure solid state and low price, but at present, the limited detection distance is mostly used for blind filling. OPA scheme has the advantages of pure solid state, high scanning frequency / precision and great cost reduction potential. However, similar to FMCW, on the one hand, there are difficulties in the design of devices, such as optical coupling loss and sidelobe interference of the chip. On the other hand, the silicon optical process is not mature. Therefore, it still takes time for this scheme to be implemented and is expected to become the end of lidar.
Transceiver module: mainly eel laser and 905nm wavelength
At present, the laser / receiver / laser wavelength is mainly eel / APD / 905nm, and the long-term VCSEL / SPAD / 1550nm has great potential. In the laser field, eel laser with high power density and simple structure in 905nm band is the mainstream at present. VCSEL has good beam quality, low temperature drift coefficient, low cost and easy integration, but the power density is insufficient and the application scenarios are limited. In the future, the power density is expected to gradually increase to replace eel. Limited by 1550nm band technology, fiber lasers are still the main ones at present. At the receiving end, the arrayed SPAD is expected to gradually replace the current mainstream APD with high sensitivity and low cost. In terms of wavelength, 905nm is simple and easy to use, which is the mainstream laser wavelength at present. However, due to the upper limit of power under the requirements of human eye safety, the distance measurement ability is insufficient. The 1550nm band can increase the power and improve the detection distance. The ambient light in this band is weak and the interference is small. At the same time, it is easier to be integrated in the silicon optical chip, which is expected to expand its share in the future.
Risk tip: the industry demand is less than expected, and the technical route has changed significantly.
