With the development of laser application technology, high-power, high-beam quality laser pointer light sources are required in many fields such as industrial processing, space optical communications, and optoelectronic countermeasures. Generally speaking, the beam quality M2<1.3 is called a single-mode laser, 1.3<M2<2 is a quasi-single-mode laser, and M2>2 is a multi-mode laser. In multi-mode lasers, 2<M2<4 can be called high-brightness multi-mode lasers.
Although high-brightness multi-mode lasers belong to multi-mode lasers, they still maintain many high-brightness characteristics of single-mode lasers. At the same time, they are better than single-mode or quasi-single-mode lasers in terms of cost control, stability, and suppression of nonlinear effects. Many, so it presents irreplaceable advantages in certain application areas.
In the realization of the technical solution, due to the theoretical limit of the power expansion of single-fiber lasers, and the difficulties of mode instability, nonlinear effects, etc. encountered in actual development, the current high-brightness fiber laser light sources above 10kW all use multiple The beam synthesis method of the fiber laser module. Beam combination is divided into two categories: coherent combination and incoherent combination.
In the field of incoherent combination, it is divided into two methods: power beam combiner and spectral beam combiner. Although compared with other new types of beam combining schemes such as spectral beam combining, the fiber power combiner will bring more beam quality degradation, but it is still the one with the earliest application, the most mature technology, the simplest scheme, and the most stable operation. Kind of way.
The first report of a multimode green laser pointer with a power combiner as its core technology was IPG. They achieved a 10.5kW multimode output in 2009 and applied for a patent. In 2013, they launched a 100kW multimode industrialized product. my country’s high-power fiber laser started late, but it has developed rapidly in recent years. For example, the 30kW industrial-grade fiber laser national key project was launched in 2017, and the 30kW industrial-grade laser was launched in 2019.