940nm high-temperature resistant 105°C chip for automotive lidar and fiber optic coupled pump module
Dogain has successfully developed a 940nm high-temperature resistant semiconductor laser chip and fiber optic coupled pump module for vehicle lidar, and passed strict performance and reliability tests, and officially launched a 940nm fiber optic coupled pump module that meets the requirements of vehicle specifications with the advantages of small size, high resistance resistance, high temperature resistance, and low temperature resistance.
Figure 1: High-performance 940 nm fiber-coupled pump module for automotive LiDAR
Application Background:
In terms of the selection of the operating wavelength of vehicle lidar, compared with wavelengths such as 905nm, the human eye safety threshold of 1550 nm wavelength is higher, and higher laser power can be emitted to achieve higher ranging sensitivity. Moreover, this wavelength is far away from the sun's infrared background light, so it has high anti-interference ability and can achieve longer-distance sensing detection. As a lidar light source, the 1550 nm fiber laser has gradually become one of the important technical solutions for lidars such as unmanned driving, vehicle safety warning, ranging, and wind measurement, and is currently a technical hotspot in the field of lidar.
At present, the solution of 940nm fiber coupled module pumping 1550nm fiber laser is the main technical way to realize the application of 1550nm lidar, which can fully meet the requirements of lidar for high peak power, short pulse and high beam quality.
Technical difficulties:
1. Extremely high temperature operating requirements of the chip: 940nm semiconductor laser chip requires excellent temperature characteristics, which can achieve high-power stable and reliable operation in a high temperature environment of ≥ 105°C;
2. Automotive level reliability: meet the performance and safety requirements of vehicle regulations for sensing components, and have extremely high requirements for product design and technology;
3. Harsh environmental adaptability: Due to the complexity of the vehicle environment, the product needs to achieve stable work in harsh vibration and shock, high and low temperature environments.
Development results:
Based on the chip R&D and production platform of the whole chain of Dogain, we have successfully developed a high-performance 940nm semiconductor laser chip around the difficult problems of performance and reliability. At 25°C, the output power of 12A is greater than 12W, and the electro-optical conversion efficiency of the coupling module is as high as 60% at 10W power, and the power output of higher than 7W can still be stably achieved under the environment of extremely high temperature of 105°C.
Figure 2: Typical photoelectric characteristic curves of a 940nm fiber-coupled pump module (25°C & 105°C)
In terms of reliability, the laser pump module has passed the mechanical vibration test of 20G acceleration and 20-2000HZ frequency, and has also passed the mechanical shock test of 500G acceleration.
In terms of environmental adaptability, this pump module has good high temperature and low temperature resistance. In 500 high and low temperature cycle tests from -40°C to 110°C, the average operating current Iop change rate was -0.2%. The wavelengths tested by the module at extreme temperatures of -60°C and 105°C are 915.3nm and 972.6nm, respectively, and are completely within the active fiber ion absorption window of the 1550nm lidar system, which can ensure the normal operation of the lidar system in the harsh environment of a large temperature range and has strong temperature applicability.
Figure 3: Spectral test curves of fiber optic coupling modules at different temperatures (-60°C, 25°C, 105°C).
In response to the demand for 940nm pump modules for automotive-grade 1550nm lidar applications, Dogain has independently developed high-performance and high-reliability 940nm semiconductor laser chips and fiber optic coupling modules. The output power of the module is higher than 12W at 25°C and 12A, and the output power of the module is higher than 7W at 105°C ambient temperature, and the product indicators meet the requirements of automotive-grade applications. In addition, Dogain has established a sound quality management system in process control, reliability verification and other links, and has the mass production and supply capacity of automotive-grade 940nm pump modules.
