Fibre Laser Marking

Fibre laser markers have a 1090 nm wavelength, making them IR (infrared) lasers. Fibre lasers can mark a wide range of materials, though they are optimised for metal marking applications. Their high output power makes them perfect for deep engraving applications as well as any marking or processing application with tight cycle time requirements.

Fibre laser markers are actually based on the same technology used for long-distance communication (optical fibres). A laser is efficiently amplified when it travels through an optical fibre, making it possible to produce a high-output fibre laser.

A Hybrid laser marker is a combination of a fibre laser and a YVO₄ laser. Fibre lasers are known for their high average power, which is especially important for deep engraving or tight cycle times, while maintaining a long service life. YVO₄ laser markers are known for their high beam quality, peak power, and versatility when it comes to marking a wide range of materials. The KEYENCE Hybrid laser has been designed to capitalise on the strengths of both of these laser markers. The built-in oscillator (S-MOPA) provides the advantages of both technologies giving the hybrid a high average power and longer service life, while also giving it the high beam quality, peak power, and overall versatility that the YVO₄ laser provides. This makes the hybrid laser marker the most versatile and well rounded laser on the market.

The main difference between the hybrid and the fibre lasers are their peak powers and their pulse widths. Peak power is the intensity of the light and pulse width is the duration of light. Hybrid lasers have the characteristic of easily creating light with a high peak and short pulse, which they get from the YVO₄ technology. Fibre lasers have the characteristic of easily creating light with a low peak and long pulse. When subjecting materials to a laser, the processing results vary greatly depending on the pulse differences.

The beam quality of a laser marker is extremely important because it can determine the energy concentration and overall effectiveness of the laser. The quality of a beam is measured with a M2 value, the closer this value is to 1 the higher the quality of the beam. This is also one of the differences between hybrid and fibre laser markers. The YVO₄ oscillator in the hybrid laser generates a beam with an M2 value less than 1.3, which is significantly better than the fibre standard around 2.

The reason that this is important is the better the beam quality the more consistent the mark and the greater the depth of focus. Depth of focus is an important factor for basic performance in order to achieve and maintain marking quality. When used in combination with the Z tracking function, this also results in a very high tolerance to height deviation, one of the most common concerns or issues with laser marking in general.

The combination of fibre technology and YVO₄ technology makes the hybrid laser one of the most, if not the most, versatile lasers on the market. With S-MOPA, high peak power, short pulse duration, and high beam quality the hybrid laser can mark almost every material. Below shows the comparison of how well UV, Green, Hybrid, Fibre, and CO₂ lasers mark a variety of materials.

A fibre laser engraves by heating the material until a point of vaporisation, leaving an engraved marking behind. Fibre lasers have a much higher output power than conventional laser markers. As a result, they're able to perform most applications at a much faster pace. Choose a fibre laser marker when you need a fast mark or a deep engrave on metal.

CO₂ lasers and fibre lasers both use infrared range light. However, they process differently. Fibre lasers use a wavelength of 1090 nm, while CO₂ lasers use 10x that—a 10600 nm wavelength. Because of the drastic difference in wavelengths, fibre and CO₂ lasers are generally purposed for very different applications.

The high heat of CO₂ lasers makes them optimal for processing transparent targets that don’t absorb fibre laser light. Likewise, fibre lasers process metals that do not absorb CO₂ laser light.

However, these lasers are both excellent for laser cutting. Both a CO₂ and fibre laser machine will excel at cutting because of their high output power.

UV lasers and fibre lasers use different methods for processing; therefore, these lasers are not interchangeable. While the fibre laser uses an infrared laser with a wavelength of 1090 nm for heating materials, UV lasers use a 355 nm UV laser. Additionally, instead of travelling through a fibre, UV lasers travel through two crystals to reach the final beam point.

Because these lasers use different methods, they process completely different materials. Since the 355 nm wavelength of a UV laser is so readily absorbed, it processes material through photolytic degradation or “cold marking.” This allows for high-contrast marking with little to no thermal impact on the product being marked. Because of the lack of heat stress, UV lasers are commonly used on sensitive materials like paper, plastic, resin, and cardboard. They are commonly used for marketing metals in specific industries where surface finish, depth, and material properties of products cannot be compromised.