In these lasers, the laser medium is composed of one or a mixture of gas or vapor. Gas lasers can be classified according to the type of transition that caused their operation: atomic or molecular. The most common of all gas laser pointer is the He-Ne (He-Ne) laser. The presence of two atomic species (helium and neon) in this gas laser may indicate that the medium is composed of molecules, but these two types of atoms cannot form stable molecules. In fact, all inert atoms such as helium, argon, k, etc.
(atoms in the last column of the periodic table) are tightly bound to their own electron cloud, and rarely form molecules or react with other atoms (hence the name: Inert). In a HeNe laser, the transition that produces output light is an atomic transition. A gaslaser engraver that uses molecular gas or vapor for its laser medium uses molecular transitions for laser operations. Molecular transitions are often more complicated than atomic transitions. As a result, laser light produced by molecular lasers tends to have a broader and more varied set of characteristics. Some examples of common molecular gas lasers are carbon monoxide (CO), carbon dioxide (CO 2), excimer and nitrogen (N 2) lasers.
CO2 metal blue laser pointer etching machine
The carbon dioxide laser (CO2 laser) developed in 1964 was one of the first gas lasers created. The CO2 laser is the highest power continuous wave laser currently available, which can generate a stable infrared light flow, and its wavelength band is concentrated on 10.6 microns. Although the specific ratio varies with the laser machine and the manufacturer, the CO2 laser usually contains about 10-20% carbon dioxide, 10-20% nitrogen, a small amount of hydrogen or xenon (<5%) and the remaining helium gas. mixture. The gas mixture is used as an electron source, which can be excited by an electric current to generate a laser beam.
The date laser etching was invented is unknown but we know that laser engraving was reported to be used for the first time in 1978. Since the two processes are very similar (laser engraving involves some level of melting), the origin of laser etching is arguably the same as laser engraving.
Here are some of the key events that led to the invention of laser etching as we know it today:
- 1917 – Albert Einstein theorizes that electrons can be made to emit light of a specific wavelength in his paper “On the Quantum Theory of Radiation”.
- 1951 – Charles Hard Townes conceives the maser (microwave amplification by stimulated emission of radiation), the predecessor of the laser (light amplification by stimulated emission of radiation). In 1954, he demonstrates that the maser works with a device that emits a wavelength of ≈1 cm.
- 1957 – Gordon Gould theorizes the laser. Almost at the same time in 1958, Townes publishes a paper that shows that masers could operate in the optical and infrared spectrum. This leads to long patent disputes, with Gould only receiving patents in 1977 and 1979. In 1988, he receives royalties for the first time after 30 years of disputes.
- 1960 – The first laser is constructed. It uses a synthetic ruby crystal (its gain medium) to amplify light.