Qianmu Laser was founded in Wuhan in November 2017 by several returning doctors who have been working in mainstream laser companies in the industry for many years. The company’s product directions are widely used in various fields such as VCSEL, DFB, narrow linewidth lasers, industrial high-power lasers, consumer electronics, autonomous driving, fiber optic communications and industrial cutting. The company launched a 940nm high-power laser in April 2018, which is used in mobile phone depth perception (face recognition, depth of field acquisition) and LiDar. Qianmu Laser successfully mass-produced 6-inch wafer 25G VCSEL chips in 12 years in 2019, which are used in data centers and consumer electronics.
In Wuhan, the epidemic center, after 77 days of fighting against the new crown virus, we finally ushered in the dawn of victory. After lifting the closure of the city in Wuhan, Qianmu also immediately handed over the communication VCSEL samples to the customer.
After Wuhan resumed work, employees returned to work one after another
In the past year, Qianmu Laser has experienced the overall design of the chip, the construction of the material system, the construction of the process and the trial production of the prototype chip. Now it can finally deliver the high-speed mass production version of the VCSEL chip to customers. Prior to this, Qianmu Laser’s 3D sensing high-power chips have been successfully introduced to the industry’s leading customers and achieved mass production. As for the difference between 25G VCSEL and Qianmu’s current 3D sensing VCSEL, Dr. Li, General Manager of Qianmu Laser’s Communication and Transmission Division, concluded that there are three main differences.
In the first aspect, the 25G VCSEL chip has high requirements on the signal modulation rate. According to the application scenario and transmission distance, it will be divided into data centers, 5G and consumer applications (such as HDMI), but the constant is the chip modulation rate and bandwidth requirements. The rising and falling edges of the 25GVCSEL signal are around 20ps (picoseconds). Relatively speaking, in order to meet the application scenarios of high-power 3D sensing, the modulation rate of the I-ToF VCSEL chip developed by Dr. Yang Xu of Qianmu Laser is 60MHz-200MHz, about 100 times the difference from 25G. The recently popular D-ToF VCSEL chip is a combination of the characteristics of these two types of chips and needs to meet both high power and high modulation rate. The D-ToF VCSEL launched by Qianmu is jointly developed by Dr. Yang and me. Qianmu was able to launch D-ToF VCSEL so quickly, precisely because of our profound technical accumulation in the fields of data communication and 3D sensing. In the second aspect, the reliability of VCSEL in the field of data communication is extremely high. VCSEL needs to work continuously in continuous modulation CW mode for at least 5 years without failure, and the maximum operating temperature can reach 85 °C. According to our aging model, the life of the 25M VCSEL chip is more than 8 years under extreme use conditions and more than 40 years under normal use conditions. It has met the requirements for chip reliability in many data communication application scenarios. The third aspect, the requirement for high-speed performance and high reliability, also increases the difficulty of 25G VCSEL in the epitaxial design and process. In the entire chip development, it is necessary for the R & D personnel to consider the interaction between the various links and carefully optimize hundreds of parameters in each process. Improper handling at any of these points may result in deterioration of chip performance and reliability. Through a large amount of data and our know-how in VCSEL epitaxial design and process, we have established a set of structural models to simulate and continuously optimize the performance parameters of 25G VCSEL.
6 inch wafer
In addition, Qianmu’s rich and stable process experience accumulated in the 3D sensing 6-inch wafer production line also guarantees the successful migration of Qianmu 25G product line from the 3-inch line to the 6-inch line. Qianmu is not only the first domestic company to provide reliable 25Gbps VCSEL products, but also the first domestic company to use 6-inch wafers to produce this product. The excellent yield guarantees a stable and reliable supply, and also guarantees the quality of customers when they are delivered in large quantities.
Qianmu Laser’s physical photo
Before the Spring Festival of 2020, thousands of 10G / 25G VCSEL chips have been provided to reliability certification factories. In the case of thousands of employees unable to return to the office, the test factories in Taiwan are still constantly feedback to us the latest progress in reliability. To everyone’s gratification, the reliability results and consistency of different chips for different batches are very good. Currently, reliability tests are being carried out for 2000-5000 hours.
The Qianmu team is convinced that the high reliability and high performance of the laser chip are the foundation of the market. Many members of the Qianmu laser team have extensive reliability experience in the world’s top semiconductor laser chip companies. On the one hand, they formulate strict standards against international benchmarks and systematically verify the reliability. The reliability of mass production continues to be stable.
