Carbon dioxide, CO₂ for short, currently does not have a particularly good reputation due to the threat of climate change. It can rightly be called the "main food" for plants. Because they need it for photosynthesis. But not only plants are dependent on CO₂, but also the technology and economy. This is illustrated, for example, by carbon dioxide laser technology. CO₂ lasers are used in a wide variety of areas and sectors - from medicine to industry and communication technology. No wonder, because one of the great advantages of these lasers is the precise and controlled delivery of energy, which already makes them an extremely versatile tool. And due to the profound research in this area, many other areas of application could be added in the future.
How the CO₂ laser works
The first CO₂ laser was developed in 1964 by US physicists Kumar Patel and Ali Javan. And this innovation is still considered a milestone in the history of laser research. But How does a CO₂ laser actually work? The way it works is based on the basic principles of laser physics and uses the special properties of the carbon dioxide molecule to generate a focused beam of light. Generally speaking, a laser is a device that produces high-intensity collimated light by amplifying the emission of stimulated radiation in an active medium. In the case of the CO₂ laser, carbon dioxide gas serves as the active medium. The technical implementation is based on a three-stage process:
- First, the CO₂ molecules in their ground state are brought into an excited state by supplying energy. This can be done by electrical discharge, chemical reactions or optical excitation. In this state, the molecules have a higher energy level than in the ground state.
- This is followed by a stimulated emission process: a photon with the right energy hits a CO₂ molecule and stimulates it to emit another photon with the same energy, which sets a chain reaction in motion. This process is called stimulated emission and ultimately leads to amplification of the light.
- In the third step, there is then a further light amplification through feedback. The light is amplified by continuous reflection between mirrors until it reaches the desired intensity level.
Industry, medicine, communication: An all-rounder with a wide range of applications
Since its invention, the carbon dioxide laser has been used for a wide variety of purposes. Its specific properties, such as high performance, precise beam quality and the spectrum of activity in the mid-infrared range, make it an all-rounder. For example, CO₂ lasers are used for industrial applications in the automotive and electronics industries. That means: The CO₂ laser is used to cut, engrave, mark or weld various materials – including metal, acrylic, wood and plastic.
The carbon dioxide laser takes on completely different tasks in medicine: Due to its high precision in controlled tissue removal, the CO₂ laser is used in laser surgery for the treatment of skin diseases, tumors or for skin rejuvenation in aesthetic procedures. The user directs the laser beam of the CO₂ laser specifically at the affected areas, thus enabling minimally invasive interventions that heal quickly.
Another important area of application is communication technology. Due to its effective spectrum in the mid-infrared range, data can be transmitted over long distances and with a high bandwidth and low attenuation. In the Laser communication in space CO₂ lasers are also used to transmit data between satellites and the earth.
Likewise could Carbon dioxide lasers are revolutionizing food production. The fact that the laser energy can be concentrated to a tiny spot without unduly affecting the surrounding food material is a major advantage that could be of particular interest in several mechanical and thermal processes. For example, microorganisms on surfaces that come into contact with food could be deactivated in this way. Non-contact cutting is also already possible, avoiding cross-contamination problems with other instruments, such as blades or water. Carbon dioxide lasers are also suitable for food marking.
Important research tool
The CO₂ laser also performs various tasks in the laboratory: Research uses it there, for example, to investigate a large number of phenomena and materials. One area in which the CO₂ laser plays an important role is spectroscopy: The CO₂ laser can be used to carry out precise and detailed spectral analysis, which researchers can use to study and determine the properties of atoms, molecules and materials. Through the targeted excitation of the matter with the CO₂ laser light and the analysis of the emitted or absorbed radiation, important information about the structure, dynamics and interactions of the objects under investigation is obtained. Another field that uses the CO₂ laser as a research tool is laser physics itself. By studying the interaction of laser light with matter, researchers can gain new insights into the physical processes and further improve the way lasers work. In addition, the CO₂ laser is used for materials research. For example, the effects of laser radiation on material samples are analyzed in order to modify their properties or to develop new materials with specific characteristics.
Current challenges in CO₂ laser technology
However, CO₂ laser technology also brings with it some unsolved issues and challenges that need to be addressed in the future. A central aspect is the efficiency of the CO₂ laser: Although the lasers are generally very powerful, industry and research are working on further increasing energy efficiency. A considerable part of the energy fed in is currently emitted in the form of heat, which leads to low efficiency, especially in older devices. However, as a result of the development of new technologies and materials, energy consumption is constantly being reduced and optimized in relation to performance. Another factor that has received increasing attention lately is the sustainability of carbon dioxide lasers. Because they are extremely low-maintenance, they are considered to be very resource-friendly. However, a long service life requires a design that is as simple as possible and requires relatively few components.
06/29/2023