Introduction
The manufacturer should be aware that fiber lasers are ushering in a new era of modern manufacturing revolution. With their ultra-precision, high-speed, and contact-free cutting, marking, and engraving capabilities, they are transforming the manufacturing landscape. Among the various industries that are benefiting from this technology are the automotive, aerospace, electronics, and medical device sectors. Fiber lasers and CO₂ lasers are considered two of the most widely used lasers in industrial environments, each with its own strengths and weaknesses.
- A laser beam uses a wavelength of 1,060 nm, and CO₂ laser technology uses a 10,600 nm wavelength range.
- To produce a high-power laser beam, Fiber lasers use solid-state optical Fiber doped with a rare-earth element, like erbium or ytterbium.
- CO₂ lasers are a gas mixture of nitrogen, carbon dioxide, and helium, which is used to produce light.
This article presents a comprehensive comparison of fiber lasers and CO₂ lasers, examining their structural differences, operational mechanisms, efficiency, maintenance requirements, and applications. At the conclusion, you will know what technology to use that fits your industry’s needs.
What is a Fiber Laser?
Fiber laser technology utilizes a solid-state laser with an optical Fiber as the gain medium. The doping substance of the core Fiber is composed of rare-earth elements like ytterbium (Yb), erbium (Er), or neodymium (Nd), which enhance the laser beam. The diode guides the light into a sharp laser beam that is used for carving and engraving on metal, plastic, and many other materials.
· Working Principle
A fiber laser follows a specific set of steps during its processing. Here are these four steps.
- A pump diode produces light that spreads to the Fiber core, and light pumping is done.
- The doped Fiber core amplifies this light as it bounces in the Fiber for better results.
- The light is amplified and appears as a focused and coherent beam of light for emission.
- The beam is passed through a flexible Fiber cable straight to the cutting or marking head for beam delivery.
· Components
A Fiber laser consists of the parts. Here is the list of them, and their combined function enables the task to be done appropriately.
- A doped glass Fiber with a rare-earth material is used for light production and amplification.
- The initial source of light from the rare earth element is initiated with the pump diode.
- The laser action starts as soon as the pump diode generates light.
- In the process, the doped Fiber core can serve as the gain medium of the laser.
- Lastly, the laser Fiber lens bends the beam to cut or engrave.
· Advantages of Fiber Lasers
Fiber lasers have revolutionized the metal fabrication world, enabling cutting, engraving, and carving on a wide range of materials.
- Stable electrical to optical conversion efficiency of up to 90%.
- No mirrors or weighty gas tubes, and it has a small size.
- No moving optical parts, and the laser Fiber has a totally sealed system.
- A fiber laser can have more than 100,000 operating hours.
- Using a fiber laser can hit the spot, which can be made as small as 90% of the CO₂ laser size, with finer detail.
- Best used with reflective metals, including aluminium, copper, and brass.
Do you know about CO₂ lasers?
CO₂ lasers, a type of gas laser that utilizes a high-power laser beam by combining gases, with carbon dioxide serving as the base, have been a reliable tool in the manufacturing industry since the 1970s. Their long-standing use and proven track record make them particularly well-suited for non-metallic materials.
· Operating Principle
- In the initial step, the nitrogen molecules of the gas mixture are excited by an electric current.
- Energy is transferred to the CO₂ molecules from the excited nitrogen molecules.
- The CO₂ molecules emit photons, and this constructs the laser beam.
- In the tube, there is an end-to-end reflection of light by mirrors till a stable laser beam is emitted via a partial mirror through optical resonance.
· Components
- The main components of the system are a gas tube that is filled with carbon dioxide, nitrogen, and helium.
- The electrodes in the system make the gas molecules get charged.
- A CO₂ laser has a mirror that focuses and increases the laser beam.
- The system has an in-built cooling system that ejects heat produced during use.
· Advantages of CO₂ Lasers
- You can use the CO₂ on different materials like wood, acrylic, glass, fabric, and plastics, which are examples of non-metal materials that are suitable for this process.
- Using a CO₂ laser gives cleaner and smoother cuts on thicker material.
- Tested and used for a long time.
- It requires less maintenance for its operation as compared to a fiber laser.
- It has a low start-up cost, which is usually less costly than fiber Lasers.
Differences between Fiber Lasers and CO₂ Lasers
There are benefits and uses for both fiber and CO₂ lasers. However, there are certain areas in which these two technologies differ as well.
Wavelength and Absorption
A gas laser and a fiber laser have different wavelengths and absorption rates. Here is the difference between the two:
| Laser type | Wavelength | Material absorption characteristics |
| Fiber Laser | 1.06µm | The fiber laser is Ideal for metals; reflective materials highly absorb it. |
| CO₂ Laser | 10.6µm | The use of a CO₂ laser is best suited for organic materials, such as wood and plastics, and it is not suitable for reflective surfaces. |
- The use of the fiber laser, which has a shorter wavelength, for getting better absorption in metal surfaces.
- The longer wavelengths for the CO₂ laser make it non-ideal for use on reflective surfaces.
Cutting Materials
Fiber lasers and CO₂ lasers have applications in material cutting; different materials have different compatibility with both technologies. The manufacturer recognizes that the fiber laser is most effective for cutting metal reflective surfaces, while the CO₂ laser is better suited for cutting organic materials, such as wood and textiles.
| Materials | Fiber laser | CO₂ laser |
| Stainless steel | Effective | Less effective |
| Aluminium | Effective | Less effective |
| Copper | Effective | Not effective |
| Brass | Effective | Not effective |
| Textile | Not effective | Effective |
| Wood | Not effective | Effective |
| Plastic | Not effective | Effective |
| Glass | Not effective | Effective |
Energy Efficiency and Power Consumption
Both technologies have different energy efficiency and power consumption. Here is the detail:
- Wall-plug efficiencies for fibre lasers are between 30% and 40%.
- In contrast, CO₂ lasers achieve an efficiency of only 5–10%.
Consequently, fibre lasers use around 70% less energy when compared to CO₂ lasers with the same power output capabilities. For instance, a 6kW CO₂ laser will approximately require 70kW of power, while a 6kW fibre laser only requires 18-20kW. Hence, the operational costs will be nearly 50% cheaper when using fibre laser systems.
Cutting Speed and Accuracy
- For thin materials, fibre lasers cut up to 3-5 times faster than CO₂ lasers, 2.0 times faster than CO₂.
- For materials greater than twenty centimetres in thickness, CO₂ lasers have a greater effect because of a smoother edge finish.
Fibre lasers also offer:
- Greater accuracy in cutting because of smaller kerf widths.
- More precise cutting regarding the reduction of the spot size.
- Improved consistency for intricate work such as engraving and micro cutting.
| Material | Fiber Laser Speed (mm/s) | CO₂ Laser Speed (mm/s) |
| 3mm of stainless steel | 55 | 20 |
| 10mm aluminium | 25 | 10 |
| 6mm of mild steel | 40 | 15 |
Maintenance and Lifespan
For any machinery to work properly, it is essential to have it inspected regularly. But certain machines require more maintenance than others.
Fiber Laser:
- The absence of mirrors or gas refills makes maintenance unnecessary.
- The fibre laser system has a competitive advantage with a usable life exceeding 100,000 hours.
- It has a sealed and compact design that minimizes possible contamination.
CO₂ Laser:
- For proper maintenance, regular mirror alignment and cleaning are required.
- The gas refill and optics replacement add unnecessary downtime.
- It has a typical lifespan of 20,000-30,000 hours.
Maintenance
After every 6-12 months, an inspection is required for the CO₂ laser. It represents a significant improvement over CO₂ lasers, which necessitate alignment and cleaning every 3-6 months.
Cost Analysis
| Category | Fiber laser | CO₂ laser |
| Initial cost | Higher | Lower |
| Operating cost | Lower | Higher |
| Maintenance cost | Minimum | Moderate to high |
| Ownership cost | Lower | Higher |
Application Scenarios
· Uses of Fibre Lasers
- It can be used in cutting, welding, and engraving stainless steel, aluminium, and copper.
- The cutting and marking of precision parts in the automobile industry.
- Trimming PCBs and marking serial codes in electronics manufacturing.
- Fiber lasers can be used to cut lightweight alloys in aerospace.
- It can be used for engraving fine ID marks in medical devices.
· Uses of CO₂ Lasers
- A CO₂ laser is used for engraving on cardboard, plastics, and glass.
- Manufacturers use it in cutting and engraving components of furniture.
- CO₂ lasers do fabric cutting and pattern design in the textile industry.
- In engraving on acrylic and glass in the signage and advertising industry.
- It can be used in engraving organic materials for decorative purposes.
Conclusion
Both fiber lasers and CO₂ lasers share some common features; however, there are notable differences between the two technologies.
- It is explained here that in the automotive, aerospace, and electronics industries, fibre lasers are quicker, more precise, and more efficient in cutting metals.
- On the other hand, CO₂ lasers are still effective for cutting non-metals like wood, acrylic, and fabrics, and they leave fine, smooth edges.
While fibre lasers are cheaper to maintain and operate, the CO₂ laser has cheaper initial costs. Ultimately, the selection will depend on the type of material, the required cutting quality, and the scale of production for the most efficient manufacturing process.