Laser In Automotive Lidar
The Background Of Automotive Lidar
From 2015 to 2020, the country issued a number of related policies, focusing on 'intelligent connected vehicles' and 'autonomous vehicles'. At the beginning of 2020, the Nation issued two plans, which are Intelligent Vehicle Innovation and Development Strategy and Automobile Driving Automation Classification, to clarify the strategic position and future development direction of autonomous driving.
Yole Development, a world-wide known consulting firm, published an industry research report associated with the ‘ Lidar for Automotive and Industrial Applications’, mentioned that the lidar market in Automotive field has the possibility to reach 5.7 billion US dollar by 2026, it is expected that the compound annual growth rate might expand to more than 21% in the next five years.
In the Automotive self-driving field, there are 2 major schools of automatic/assisted driving, which are pure visual school and different sensor fusion schemes such as Lidar. For now, Lidar is increasingly favored by a growing number of enterprises, occupying an increasingly important position with its advantages of ranging ability, high resolution and anti-interference,which has been a crucial supplement available for camera, millimeter wave radar and other detection approach.
As the ‘Eye’ of the automotive vision, the performance of Lidar has the core influence,directly affecting the safety of the self-driving/assist-driving. The higher peak power of the Lidar transmission, the farther detection it will be, also, the higher corresponding spatial resolution and detection sensitivity, the less interference will caused by the weather.
In the automotive laser lidar market, EEL type 905nm semiconductor laser with simple, compact structure and low cost comparing to other components has become the mainstream Lidar laser source. However, there are some limitation adopting this module due to the material it made of and the wavelength interval. So far it cannot meet the human eye-safety wavelength requirements and operate in the model of high refrequency and narrow pulse causing the loss of ranging ability. In a way, the characteristics become an obstacle to its further development.
With its unique circular beam transmitting capability, VCSEL laser has certain advantages in improving radar resolution and greatly simplifying the cost of beam shaping. However, its relatively short development history and low transmitting power greatly limit its application in lidar direction.
Schematic diagram of human eye structure
In the development of the automotive unmanned field, the 3 core aspects are considered to be : environmental perception and localization, decision planning, and execution control. For achieving a mature and safe unmanned technology, the first step is to overcome the technical challenges in this part of environment perception. Environment perception means to monitor the environment around the participants of autonomous driving behavior (such as unmanned cars, unmanned aerial vehicle, etc.) and integrate information through cameras, sensors and LIDAR. Traditional LIDAR used to use 905nm wavelength near-infrared lasers, which are relatively mature and low cost. However, the output power of the laser is obviously limited considering the safety requirements of human eyes. Meanwhile, there is more NIR background light in sunlight, and the signal-to-noise ratio of the sensor is physically limited, and the maximum detection distance is restricted to about 150 meters.
What We Offer
The 1550nm infrared laser developed by Lumispot Tech has a much higher safety limit than 905nm (about 2 orders of magnitude), and because of the longer wavelength penetration is better, so the background light interference problem is relatively ignorable, more conducive to use in rainy and foggy weather, and can achieve long-distance detection and rangefind. At the same time, using coherent technology, the detector only responds to the laser echoes emitted by itself. Its signal-to-noise ratio is much higher than that of 905nm-ToF LIDAR, and the maximum detection distance can reach more than 1000m and several kilometers in special scenarios. Due to unique pump modulation technology, this lidar avoids a lot of ASE noise and power consumption caused by the pump being normally open, which is also a significant advantage among similar products in the market.
1550nm Fiber Laser Power Amplification Simple Flowchart
Mini PULSED FIBER LASER
Latest 1.5μm Micro pulsed fiber laser was launched by Lumispot Tech in the recent years, which is further optimized in volume, weight ,power consumption and other technical indicators based on the small-size pulsed fiber laser. With the most compact structure and the relatively less power consumption comparing with the similar products in the laser market, it is considered as the most suitable laser light source for Automotive Lidar.
Core Technology Used：
- Laser integration technology
- Narrow pulse shaping technique
- ASE noise suppression technology
- Compact space disk fiber process
The Trend Towards 1550nm Fiber Lasers
In summary, the choice of laser source is pivotal in determining the performance of Lidar systems. While traditional semiconductor lasers at 905nm have been widely used, they come with limitations that hinder Lidar's full potential. In contrast, the adoption of 1550nm wavelength fiber lasers represents a significant trend in high-end Lidar system development.
These lasers offer eye-safe operation, resistance to interference, extended detection ranges, and improved image quality. Moreover, the use of coherent techniques enhances signal quality, enabling Lidar systems to excel in various applications, including autonomous driving, laser rangefinding, remote sensing, and security surveillance. The evolution of laser sources towards 1550nm is set to revolutionize Lidar technology, paving the way for safer, more efficient, and high-performance applications.