Progress in Production Technology Of Laser Pump Source

The core components in the pump source include laser chip and slow-axis collimator (SAC), fast-axis collimator (FAC), polarization beam splitter/beam combiner (PBS/PBC), mirror (Mirror), focusing lens (Focusing lens), optical fiber head (FTA) and other laser optical components. Each pump source needs to use 1 polarization beam splitter/combiner, 1 focusing lens and 1 fiber head. The number of laser chips used depends on the power of the pump source and the power of a single chip, and each laser chip needs to be combined with 1 slow-axis collimator, 1 fast-axis collimator and 1 reflector are used together.

At present, Raycus and MAX have gradually realized the comprehensive independent packaging of pump sources and COS chips, but there is still a certain gap between high-power laser chips and imported chips. At present, the power of the pump source on the market is mainly 100 W-400 W, and it is showing an increasingly high development trend. Raycus' 350 W, 370 W, and 500 W pumps have achieved mass production. At present, the pump module can achieve a maximum output of 700-1000 W, and the NA of 95% of the energy is within 0.17. MAX has already achieved self-made COS chips in 2017.

The laser chip is the core component of the semiconductor pump source, and its power level and performance stability directly affect the output laser performance. Laser chips are a very weak link in the domestic laser industry chain. For a long time, almost all high-power laser chips in my country have been imported. The import price is relatively high and there are technical blockades. American companies such as Lumentum and II-VI have the capability to manufacture high-power laser chips and can export them, while American IPG, German Trumpf, and Nlight can manufacture such chips but do not sell them. Domestic companies such as Everbright, BWT, Huaguang and other companies have independent design capabilities for chip packaging technology. At present, Raycus mainly purchases chips and pump sources from Everbright and BDL. According to its estimated daily related transaction plan in 2022, the purchase amount in 2022 will reach 400 million yuan. MAX also began to develop its own single-tube pump source in 2017.

According to the Everbright prospectus, the market size of laser chips in my country's domestic market in 2020 is 529 million yuan. According to the "2021 China Laser Industry Development Report" data [1], in 2020, my country will ship about 38,000 fiber lasers with 1-3 kW, about 14,000 with 3-6 kW, and 6-10 kW. About 2,400 units were shipped, and about 1,600 units were shipped over 10 kW, as shown in Table 1. According to the calculation of Optoelectronics, in 2020, my country's fiber laser shipments will roughly total 56,000 units (about 194,000kW), and it is expected that the total fiber laser shipments will exceed 100,000 units (about 309,000kW) in 2021. According to the light-to-light conversion rate of the commonly used pump sources in the market, about 70%, about 70% of the industrial single-chip power is 20 W, and 30% of the industrial single-chip power is 10 W, the consumption of industrial laser chips in 2020 is about It is 20 million tablets, and the expected consumption in 2021 is 31.9 million tablets.

Among the domestic R&D teams engaged in laser chips, Everbright is at the forefront. In 2021, its total revenue has reached 429 million yuan, and its net profit has reached 115 million yuan. Its high-power semiconductor chips have a leading domestic market share. At present, Everbright has gradually realized the localization of single-tube chips with high power, high reliability, high efficiency and wide wavelength range. The mass production power can reach 30 W, the wavelength range covers 808-1064 nm, and the electro-optical conversion efficiency reaches 60%-65%. %, the product technology level is synchronized with the foreign advanced level, and the downstream customers cover domestic mainstream laser manufacturers such as Raycus, MAX, HANS, and FEIBO. Affected by the overall price drop in the industry chain and the competitive strategies of domestic and foreign manufacturers, chip prices also showed a downward trend. Everbright has been successfully listed on the Science and Technology Innovation Board, and the localization of laser chips is the general trend.

Optical components are also an important part of the pump source, whose damage threshold, coaxial accuracy, and coating quality directly affect the output laser performance. Among them, the fast-axis collimator is a non-cylindrical microlens, which is technically difficult. Only a few companies in the world have mastered the processing technology. The main suppliers in the market are Limo, Fisba, Svetwheel, etc. A few years ago, the domestic product was completely dependent on imports, but after Focuslight acquired Limo and Haichuang independently developed FAC products, domestic FAC has been replaced by domestic products, and the technology has reached the international leading level. Slow-axis collimating lenses, mirrors, polarization beam splitters/beam combiners, focusing lenses, coated optical fibers and other pump source optical components have all been replaced domestically. At present, the main suppliers are Haichuang, Focuslight, Fisba, Ingeneric, II -VI etc. The optical components of the pump source of the IPG fiber laser are produced and used by themselves, and are not sold to the outside world.