The principle of fiber laser cutting machine – internal optics and external optics

The Principle of Fiber Laser Cutting Machine – Internal Optics and External Optics


Fiber laser cutting machines have revolutionized the metal fabrication industry with their precision and efficiency. These machines utilize advanced technology and a unique optical system to achieve precise cutting of various materials. In this article, we will delve into the principle of fiber laser cutting machines, focusing on their internal optics and external optics.

Internal Optics

The internal optics of a fiber laser cutting machine play a crucial role in delivering the laser beam to the material being cut. The main components of the internal optics system include the fiber laser source, beam delivery system, and focusing lens.

The fiber laser source generates the laser beam using a process called stimulated emission. This involves pumping energy into a specially designed fiber optic cable doped with rare earth elements such as ytterbium or erbium. As the energy passes through the fiber, it stimulates the emission of photons, resulting in a high-intensity laser beam.

The beam delivery system is responsible for guiding the laser beam from the fiber laser source to the cutting head. It consists of mirrors and lenses that carefully direct the beam along a predetermined path. Additionally, the beam delivery system may include a beam expander to adjust the size of the laser beam, ensuring optimal focus during the cutting process.

The final component of the internal optics system is the focusing lens. This lens focuses the laser beam to a small spot size on the surface of the material being cut. By concentrating the energy in a small area, the focusing lens allows for precise and efficient cutting. The distance between the lens and the material, known as the focal length, can be adjusted to achieve different cutting depths and speeds.

External Optics

The external optics of a fiber laser cutting machine are responsible for controlling and manipulating the laser beam during the cutting process. These optics ensure that the focused laser beam accurately follows the desired cutting path.

One of the essential components of the external optics system is the cutting head. The cutting head contains a nozzle through which assist gas, typically oxygen or nitrogen, is directed towards the cutting zone. This gas removes molten material from the cut, helping to achieve a clean and precise edge.

Another critical element of the external optics system is the motion control system. This system controls the movement of the cutting head along the X, Y, and Z axes, allowing for precise positioning and cutting. The motion control system is usually driven by motors and guided by sensors and feedback mechanisms to ensure accuracy and repeatability.

To monitor and maintain the cutting process, fiber laser cutting machines also incorporate sensors and cameras. These devices provide real-time feedback on the cutting parameters, material properties, and any abnormalities during operation. This information allows operators to adjust settings and optimize the cutting process for improved results.


Fiber laser cutting machines rely on a sophisticated internal and external optics system to achieve precise and efficient cutting. The internal optics deliver the laser beam to the cutting head, while the external optics control its movement and ensure accurate cutting. By understanding the principles behind these optical systems, manufacturers can harness the full potential of fiber laser cutting technology and enhance their metal fabrication processes.

In conclusion, the combination of advanced internal and external optics makes fiber laser cutting machines a valuable tool for various industries. Their ability to cut through metals and other materials with high precision and efficiency has transformed the manufacturing landscape and opened new possibilities in design and production.

The principle of fiber laser cutting machine - internal optics and external optics