Fiber laser is a recognized power in many industries and manufacturing industries because of its throughput, reliability and low operating cost. It enables fiber lasers to be used for cutting, welding, marking and micromechanical materials machines. Specific design elements distinguish fiber lasers from industrial laser sources. Their unique attributes make breakthrough manufacturing process capabilities possible. Specifically, high-power single-mode lasers and flexible pulsed fiber lasers used for remote welding can respond to different process challenges by electronically controlling operating parameters.

Fiber lasers excel at converting relatively low-brightness pump light from laser diodes into high-brightness output. The quality of the output beam is usually the only spatial mode, which is allowed by fiber design physics, even though fiber lasers can.

A very high output power (100 W) was reached as early as the 1990s. After the collapse of the optical fiber communications market in 2001, reliable fiber lasers were commercially developed. In the 1990s, the reasarcher spent billions of dollars to solve the basic problem of coupling diodes to high-reliability optical fibers and splicing high-power-density optical fibers to make the component technology meet the 25-year reliability requirements of subsea communications and reduce these costs and to be high-performance, high-reliability components.

Then in the early 2000s, with the disappearance of the communications market, technology investment quickly shifted and adjusted to designs for industrial fiber lasers.

Fiber laser is unique among all types of industrial lasers because it has two properties: a sealed optical cavity and a single-mode guided wave medium. By design, modern fiber lasers have a completely sealed optical path, free from environmental pollution and can maintain optical alignment without adjustment. All internal components are fiber-coupled or air-tight fiber-coupled and the only free space interface appears on the beam delivery optics， which includes a fused beam expander that reduces the intensity at the first free space interface. The active optical path is usually in a fiber waveguide, which allows only one spatial mode to propagate (current optical power is up to 2 kW).

High-power fiber lasers combine single-mode modules into high-brightness transmission fibers in a fusion fiber combiner. The combination of a single-mode waveguide and a completely sealed optical cavity provides a reliable laser design that can be fixed and measured at the time of manufacture with minimal changes over time and temperature. Sealed pump diodes and non-bare fiber technology can produce lasers that can be produced continuously for many years without adjustment or performance degradation.

At power levels of 4 to 8 kW commonly used in many metal cutting and welding markets today, the comparison of fiber lasers and disk laser sources are basically academic. From the user's point of view, both provide almost the same power, beam quality, wavelength, reliability and beam delivery options. Choosing a laser in this power range will be based on commercial considerations of service, support and value-added features, all of which have nothing to do with the underlying resonator technology. Successful fiber laser manufacturers have solved the engineering problem of fusing glass to withstand the strength of meltable or ablative metals, and successful disk laser manufacturers have solved sophisticated optical mechanical thermal design to provide stable high brightness output.

Since the disc laser is not a sealed cavity, it has several basic advantages compared with fiber lasers. The high frequency conversion efficiency in the cavity makes the disk perform better when generating harmonic frequencies (green and ultraviolet wavelengths). In addition, it is easier to implement cavity design for ultrafast (picosecond and femtosecond) lasers. Compared with fiber lasers, disk lasers can achieve higher peak power and higher pulse energy. This is due to the fact that fiber lasers must be designed within the limits of competing nonlinear effects (such as stimulated Brillouin scattering), and nonlinear effects appear due to the cumulative interaction length of the fiber waveguide.

Battery manufacturing involves the connection of metal foils and metal sheets at all stages, from the bag to the battery to the complete battery assembly. Due to productivity and welding strength, laser welding is becoming more and more popular than ultrasonic and resistance welding. In addition, laser welding is a non-contact process and does not involve tool wear. By using the brightness and dynamic capabilities of fiber lasers, the specific challenges of joining dissimilar metals that were previously considered unweldable can be solved.

Fiber lasers that provide a single-space mode output power of more than 1 kW, which has the required brightness to take advantage of the speed and tool path flexibility of the galvanometer scan head. The Gaussian intensity distribution allows effective reflection of even reflective metals, and the high-speed point movement of the scan head limits the molten state of the weld, thereby reduces the formation of brittle intermetallic compounds when connecting dissimilar metals.

In addition, a spiral or swing is applied to the movement of the points to "stir" the molten weld to the required weld width to achieve the required weld strength and electrical conductivity.

Until recently, single-mode lasers could not produce wide and strong welds in single-line welds. However, using swing technology, parameters can be set to meet the requirements of the application while taking advantage of the high brightness and peak intensity of the Gaussian beam.