Compared with the traditional Nd: fiber laser, the electro-optical conversion efficiency and beam brightness (single mode or low bit operation) are significantly improved, and no preheating is required. When the power is changed, it is flat top mode (as shown in Figure 1), or Gaussian mode, the spot diameter is always stable, at the same time, the pulse frequency is higher, and the real-time adjustment performance of the parameters is stronger. Because fiber lasers utilize a single emitter excitation, there is a qualitative leap in reliability, power stability, and flexibility over flash-pumped lasers.
Figure 1
The aviation field is undoubtedly another industry that has benefited a lot from fiber lasers. In the current aviation industry, a turbo engine can have millions of holes, which are mainly used to help the device dissipate heat during operation. The thickness, angle, diameter, and shape of the holes are different. In the field of drilling applications, the new fiber laser is a faster, more flexible, more stable, and more cost-effective option.
There are two main ways to produce aerospace cooling holes: one is to use multiple pulses to form a hole according to the required aperture (pulse drilling); the other is to use a small spot to move the beam in a circular range to form a hole ( Set of holes). In general, the hole is slow, but the shape is more perfect. In some applications, only set of holes can be selected. These holes are typically 0.015–0.030 inches in diameter (as shown in Figure 2).
Figure 2
There is also a special drilling requirement in the aerospace field, which is the fan-shaped hole connecting the restrictor holes (as shown in Figure 3). These scalloped holes are the outlets for the cooling air, and the purpose is to divert the same amount of air to a larger range for better cooling. When drilling a fan-shaped hole, it is necessary to avoid the peeling of the thermal barrier coating, and now most devices have a thermal barrier coating.
Figure 3
