In the past 40 years, laser technology has written countless success stories in a wide range of applications, and even now there are many applications that could not be achieved without laser pointer. This article will introduce you to the development of laser technology in the field of macro-material processing from the industrial breakthrough of laser light source to the continuous improvement of application technology.
Laser material processing began in the second half of the 1960s. Pulsed solid-state lasers were first used for drilling and spot welding applications, and continuous wave CO2 lasers were used for cutting and continuous wave welding. Macroscopic laser applications (cutting, welding, hardening, cladding, etc.) were introduced into industrial production practices in the late 1970s and early 1980s. CO2 lasers were very popular light sources at the time because they had the highest processing efficiency at the time and could meet the power requirements required by industrial production.
Not all technologies and components are available in the early days. Lasers, optical components for beam transmission, focusing components such as lenses and off-axis parabolic copper mirrors, gas nozzles, processing techniques, and gas supply systems must all be developed and optimized for high power and industrial environments. In addition, all safety regulations have yet to be developed and standardized internationally. At the same time, standards for beam quality definition and measurement have yet to be developed.
With the increasing interest in laser processing in the industrial field, the demand for reliable laser processing systems in the industrial field has begun to grow. For CO2 laser sources and systems, copper optical elements and low-loss ZnSe transmission elements have reflective or anti-reflection film coatings, which are of great value for resonator elements, beam transmission and focusing. A major development at this time was the highly reliable and durable molybdenum-coated focusing lens for welding applications. In order to ensure consistent cutting quality, a cutting head with automatic nozzle remote control and optimized airflow has also been developed.
At that time, there were three different competing technologies in the CO2 green laser pointer market. These three technologies were mainly distinguished by the type of gas cooling: slow flow high beam quality medium power (about 150 W) lasers, cross flow and fast axial flow lasers, with power up to 20kW. An additional distinguishing technique is the type of gas discharge excitation. The gas can be excited by direct current (DC) discharge, which is more efficient; or it can be excited by RF discharge. The advantage of this method is that the electrode can be located outside the gas tube, which helps to keep the gas clean.