Take you to know ultrafast laser micromachining
With the continuous development of laser technology, laser processing equipment of several kilowatts has emerged, and combined with technologies such as photoelectric tracking, computer digital control, and industrial welding robots, the automation level and use functions of laser processing have been greatly improved.
Laser processing equipment is composed of four parts, namely laser, optical system, mechanical system, control and detection system. At present, what new processing technologies are there in the industry?
Understanding ultrafast laser micromachining
Everyone is no stranger to laser processing. CO2 lasers, fiber lasers and semiconductor lasers are the mainstream lasers in current industrial applications, in the order of subtle and nanoseconds, but in the past ten years, ultrashort pulse laser finishing technology has made rapid progress. In the femtosecond and picosecond order, which is what we are talking about today!
People have tried to use laser for micromachining very early. However, the long pulse width and low laser intensity of the laser cause the material to melt and continue to evaporate. Although the laser beam can be focused into a small spot, the thermal shock to the material is still large, which limits the accuracy of processing.
Only by reducing the thermal influence can the processing quality be improved. When the laser is applied to the material with a pulse time of the order of picoseconds, the processing effect will change significantly. As the pulse energy rises sharply, the high power density is sufficient to strip the outer electrons. Because the laser interacts with the material for a very short time, the ions are already ablated from the surface of the material before the energy is transferred to the surrounding material, which will not bring heat to the surrounding material, so it is also called "cold working" . With the advantages brought by cold processing, short and ultrashort pulse lasers have entered industrial production applications.
How fast is it super fast?
The pulse width generated by short-pulse lasers is defined in the order of picoseconds and femtoseconds.
One picosecond is equal to 10-12 seconds, and one femtosecond is equal to 10-15 seconds. It may be more abstract, but we can compare it in the form of distance. For example, the speed of light is 3x108 meters per second, the time required for light to travel from the earth to the moon is about 1.3 seconds, and the distance of light movement in 1 picosecond is 0.3 mm!