According to the after-sales feedback of SHINHOP Laser on battery cell laser welding equipment over the years, many customers often inquire about the issue of single-mode and multi-mode switching of laser welding machines. Whether the fiber laser they use can be directly switched to multi-mode mode? Want to try another mode to solder other products.

In fact, the answer is obvious. Fiber lasers cannot be switched between single-mode and multi-mode at any time during use. This also shows that users have not yet understood fiber lasers. It can be said that single-mode and multi-mode are two different lasers. Which one should the user use? For this mode of laser, you need a professional laser equipment company to configure it more scientifically for you. So what is the difference between single-mode and multi-mode, and what do they mean?

The module composition of fiber lasers is divided into two types: single-mode and multi-mode. In cutting applications, the focused spot has a great impact on the quality of the cut. The fiber core of single-mode lasers is thinner, and the beam quality is better than multi-mode. The energy distribution it is a Gaussian distribution, with the highest energy density in the middle, and the three-dimensional image is like a pointed round mountain peak.

1. Different fiber core diameters

1. Multimode: The core diameter of multimode optical fiber is mostly 50μm/62.5μm.

2. Single-mode: The core diameter of single-mode optical fiber is mostly 9μm.

The fiber core of the multimode laser is thicker, the beam quality is worse than that of the single-mode laser, and the energy distribution is more average than that of the single-mode laser. The three-dimensional image looks like an inverted cup. Judging from the steepness of the edge, the ratio of the multimode laser is Single mode is much steeper.

2. Different light sources

1. Multi-mode: Use LED (light emitting diode) or vertical cavity surface emitting laser (VCSEL) as the light source, because LED light source can produce many modes of light (light is more dispersed).

2. Single mode: Use laser or laser diode as the light source, because the laser light source can produce a single mode of light and has the advantages of high brightness and high power.

3. Different dispersion

1. Multimode: The refractive index of multimode optical fiber is divided into two types: gradient and step.

2. Single-mode: The core of single-mode optical fiber is mostly made of a single material and has an ancient refractive index.

5. Different costs

1. Single-mode optical fiber has a wide transmission frequency and a long transmission distance, but it requires a laser source and the cost is high.

2. Multimode optical fiber has low transmission speed and short distance, but its cost is relatively low.

6. Different numbers of transmission modes

1. The core diameter and dispersion of mode fiber are small, allowing only one mode of transmission.

2. Multimode optical fiber has large core diameter and dispersion, allowing hundreds of modes of transmission.

7. Different wavelengths

The working wavelength of multi-mode optical modules is generally 850nm, and the working wavelengths of single-mode optical modules are generally 1310nm and 1550nm.

The advantage of single-mode lies in thin plates, while the advantage of multi-mode lies in thick plates. Single-mode and multi-mode have no comparative value with each other. They are both configurations of a fiber laser, just like a car. A car is suitable for roads, and off-road is suitable for mountains. However, cars can also run in the mountains, and they can also run on roads off-road. Therefore, whether to choose multi-mode or single-mode fiber lasers depends on the actual processing needs of the end customer.

So how should we choose between single mode and multi-mode?

【↑↑↑↑Single-mode laser welding equipment commonly used for battery core welding↑↑↑↑】

From the perspective of power level distinction, lasers below 3000W use single-mode mode, which is preferred for welding or cutting work pieces with thinner materials. High-power lasers often use multi-mode, and single-mode energy is more concentrated. Multi-mode energy distribution is relatively balanced, so the two modes are based on different needs, and there is no difference between one mode and one mode. At the same time, the core of single-mode fiber is generally thinner, which means that the same power of laser is transmitted in it. The light energy of the single-mode fiber core is greater, which is a test for the material. At the same time, when cutting high-reflective materials, high-intensity reflection when light and emitted laser are superimposed, if the tolerance of the fiber material is insufficient, it will be very easy to "burn the fiber core". At the same time, it is also a challenge to the life of the fiber core material!

Therefore, many laser manufacturers still choose multi-mode configurations for the configuration of high-power fiber lasers (above 5000W).

Judging from the current situation of welding products in many battery core factories, the power of the laser used is generally below 3000W. Using single-mode laser can be said to be a good choice. Of course, the user's process requirements also require the use of multi-mode lasers. Mode to complete welding. The two modes are incomparable. Everything is allocated according to needs, and there is no question of whose quality is better.

【At last】

Single mode and multi-mode are independent of their respective fiber lasers. Until now, there is no function in the international market that can switch modes at any time on the same laser, but we cannot deny that it can be realized in the future, but at least it still needs the world Scientists should work hard to innovate.