Title: The Three Main Types of Lasers for Cutting
Introduction
Lasers have become an indispensable industrial cutting technology across a wide range of materials thanks to their precision, speed, quality, and flexibility. There are several different laser types leveraged for cutting, each with unique capabilities tailored to optimal applications.
In this blog post, we will examine the three most common laser sources used for industrial cutting – CO2 lasers, fiber lasers, and diode lasers. We will compare their fundamental operating principles, beam properties, typical uses, advantages, and limitations to provide an overview of the cutting lasers available.
CO2 Laser
The carbon dioxide (CO2) laser remains the most prevalent industrial cutting laser type, especially for thicker metals. CO2 lasers utilize an electrically stimulated gas mixture as the lasing medium. Here are key details on how CO2 lasers work and their cutting abilities:
- Operating Principle: CO2 laser excitation is produced through gas discharge between tungsten electrodes through a mix of CO2, nitrogen, and helium. This generates infrared light at 10.6 microns.
- Beam Properties: CO2 lasers emit a continuous infrared beam with excellent power capabilities up to 25 kW. The infrared wavelength yields a rather large spot size and lower beam quality.
- Cutting Advantages: The high powers and IR absorption by metals allow cutting of thick steels up to 1 inch, stainless up to 3/4 inch, and aluminum up to 1/2 inch. Lower running costs than other lasers.
- Limitations: Limited by slower pulse frequencies than other lasers. Higher operating costs from gas consumption. Infrared wavelength has reduced visibility and can only propagate through optics limited to ZnSe or Germanium.
- Typical Uses: Mid to thick range cutting of mild steel, stainless steel, aluminum, galvanized, and titanium. Also used for cutting wood, textiles, paper, and some plastics.
Fiber Laser
Fiber lasers utilize silica glass fiber optic cable as the lasing medium, combined with high-power laser diodes as the pump source. Details include:
- Operating Principle: Fiber laser excitation comes from integrated laser diodes that pump light into the central fiber core doped with rare earth ions that emit the laser beam.
- Beam Properties: Fiber lasers emit a near-infrared laser between 1.05-1.10 microns. The solid-state construction allows exceptional beam quality with high focusability.
- Cutting Advantages: Fiber’s shorter wavelength allows smaller spot sizes and intricate features. The exceptional beam quality enables tight focus and small kerfs down to 0.003 inches. High cutting speeds up to 40,000 inches/min.
- Limitations: Lower power limits fiber lasers to thinner material cutting. Maximum of about 1/4 inch mild steel and 1/8 inch stainless steel. Limited impact on non-metals.
- Typical Uses: Thin sheet metal cutting. Ideal for delicate, high-precision cuts into thin stainless, mild steel, aluminum, and copper.
Diode Laser
Diode lasers directly convert electrical energy into coherent laser light within a semiconductor diode junction. Properties include:
- Operating Principle: Direct laser emission from a diode forward biased above the lasing threshold, typically GaAs or GaN semiconductors. No separate pump source is required.
- Beam Properties: Diode lasers emit from 800-980nm wavelengths. Lower beam quality but reliable and efficient. Allows modulation up to kHz frequencies.
- Cutting Advantages: Compact size. No moving parts enhance reliability. Low-cost ownership. Rapid modulation ability enables optimizing absorptivity when cutting reflective materials.
- Limitations: Lower average power capabilities topping around 1kW. Restricted to thinner materials under 1/8 inch. Higher beam divergence impacts cutting quality.
- Typical Uses: Excels at sensitive, fine feature precision cuts into thin metals and electronics. Useful for soldering, welding, and cladding.
In summary, CO2 lasers offer unmatched thick section cutting capacity thanks to high infrared power levels. Fiber lasers provide the utmost precision on thinner metals. Diode lasers enable reliable ultra-fine processing and precision fabrication. Leveraging the right laser-cutting technology allows optimizing manufacturing processes across many industries.
Conclusion
The three major laser types of CO2, fiber, and diode each provide unique benefits for industrial cutting that suit different material thicknesses, precision needs, and production environments. Understanding CO2’s deep penetration, fiber’s tight precision, and diode’s fine control facilitates selecting the ideal laser cutting equipment.
With ongoing advances in laser technologies, beam delivery, and system integration, lasers continue growing as a preferred cutting method globally across manufacturing. Combining these powerful, flexible laser-cutting tools with automation and intelligent machine control enables smart, digital production solutions that will shape the future of industrial fabrication.