Many have argued that the technological improvement of the laser cutter is more efficient and more accurate than any of the other lasers out there. This, in itself, is a huge part of why so many companies are updating their machinery and turning to fiber lasers.
This system is located in an optical fiber, and the laser beam is created in that fiber. This is different than traditional lasers, since the traditional beam was created outside of the system and then sent into it. Based on the difference in their build design, fiber lasers are seen as being in their own category, called solid-state laser.
Everything is being generated and created in one system. The medium that is being used in a fiber laser is an optical fiber. This optical fiber is doped in rare elements, which usually include erbium, ytterbium, neodymium, dysprosium, thulium, holmium or praseodymium. Instead, gas lasers use carbon dioxide or helium-neon and crystal lasers use Nd:YAG. The reason that the fiber laser is doped in rare elements is based on their atom levels.
These elements have very powerful energy levels, and that allows for a more-affordable laser pump to be used, while still getting the same amount of energy and power from the laser. What Does a Fiber Laser Do? Fiber lasers, particularly nanosecond pulsed lasers, are also used in the processing of silicon, gemstones including diamonds , plastics, polymers, ceramics, composites, thin films, brick, and concrete too.
We have pulsed fiber lasers, continuous wave CW fiber lasers as well as ultrashort pulse laser. Pulsed fiber lasers deliver the laser beam in pulses, and you can control the duration of each pulse in the nanosecond to microsecond range. CW lasers deliver a continuous laser beam, but still has the capability for the beam power to be modulated up to the kHz frequency range.
A pulsed fiber laser is often chosen for several processes over a continuous wave beam as it is capable of higher peak power within a short pulse. Next to that micro lasers have pulse durations even shorter than picoseconds, down to fs femtoseconds. Fiber lasers are useful for many sectors around the world. For some heavy industrial applications, where efficiency and speed are paramount, a CW fiber laser that requires little to no maintenance or upkeep is the perfect solution.
That's way CW lasers are most adept at performing laser drilling, laser cutting and laser welding. If you are working with very finite materials and need very specific incisions made in complicated shapes, then a pulsed fiber laser is best suited. Laser welding is the process of welding materials together, whether this is for the joining together of similar or dissimilar materials.
Laser welding is an application that businesses simply cannot afford to ignore for quality and cost reasons. Welding is achievable for many materials and for a variety of thicknesses. Welding is used in a wide variety of applications including thick steel plates, fuel cells and batteries through to fine wires for medical device manufacture. Benefits of fiber laser welding include ultimate precision, the creation of complicated joins, application of consistent and highly repeatable welding joins as well as incredibly high strength welding joins.
Laser cutting is a process where a material is cut using a laser beam. The process simply involves the use of a focused laser beam e. Fiber laser cutting benefits include improved speed, eliminated tooling charges, reduced set-up and down times, reduced power usage and costs, much less material waste, and all through a non-contact process which is safer and avoids contamination.
Additive manufacturing is the process of building up a 3D component by adding layer upon layer of material deposit. Using a combination of 3D printing machines and computer software, complex shapes can be created. The fibre laser often serves as a beam source within the 3D printing systems. Laser ablation is the process of precision layer removal by a laser. This could be the removal of a wide range of materials ranging from solid metals, ceramics, and industrial compounds. Ablation is popularly used in applications such as elements used within electronic products e.
A major benefit of this process is that ablation is completed with high levels of precision and accuracy. Ablation is achieved in one step; this is a considerable advantage as traditional methods are almost always multi-step.
Laser ablation are more cost-effective and environmentally friendly technique than traditional methods e. Laser cleaning is the process by which contaminants, debris, or impurities e. This is a low-cost and environmentally friendly laser application technique. There are two types of laser cleaning processes, one which is the removal of a layer on the surface of a material whilst the second is the removal of the entire upper layer of a material.
Benefits of laser ablation include improved eco-friendliness as no chemicals or solvents are used and there is minimal waste , less substrate wear and laser cleaning of micro components especially in electronics. The material is vapourised and melted layer by layer until drill holes are created.
This process differs depending upon the material thickness, the number of holes that need to be created, and the size width and depth of these holes. In laser marking, the marking is applied directly onto the surface using an intensive pulsed laser beam. The interaction of the laser beam with the component surface leads to a change in the material, which produces a visible discolouration, structuring or marking. A wide variety of materials is also available for laser marking. Laser markings can be created not only on all metals, but also on ceramics, plastics, LEDs, rubber, graphic composites, etc.
Laser engraving is the process of removing a portion of material to leave a visible engraved mark. The engraving process is produced by the laser beam removing material to create a mark, where the laser acts like a chisel and blows away selected areas of the subject material. This is 'stimulated emission', as the photons are stimulating the electrons to emit more photons. Because of the way the photons are encouraging one another into existence, they are all the same colour, and they are all in step with one another.
Now we have an army of photons marching in step together, something you don't find in nature. If at this point all the photons rush out of the material, it doesn't work terribly well. We need to keep on 'pumping' the electrons back up so they are ready to emit photons, and we need to keep the photons zipping backwards and forwards to encourage even more to come out! The way we do this is by putting two mirrors in place at either end of the material called the 'laser medium'.
This creates what is called the 'laser cavity'. The mirrors reflect the light backwards and forwards, and on every round trip, more and more photons are generated. The newly-created laser light needs to be let out in order to be useful, so one of the mirrors doesn't reflect everything. Instead, it lets a tiny percentage of the light out, and that is our laser beam. One of the most common types of fibre lasers is the Erbium-Doped Fibre Laser.
We use an otherwise-normal optical fibre,made out of silica glass. We add to it very small amounts of the rare-earth element Erbium. The small particles of Erbium are mixed in to the core of the fibre when it is made. This process of introducing small amounts of another element is called doping.
The reason we use Erbium is because the Erbium atoms have very useful energy levels. There is an energy level that can absorb photons with a wavelength of nm, and this then decays to a meta-stable state equivalent to nm. This means that we can use a cheap diode laser'pump source' at nm and we get a very high quality, and potentially very high power beam out at nm.
Within the doped fibre, we have our 'laser medium', which is the erbium atoms. The photons that are emitted are confined inside the fibre core. To create our laser cavity, we add Bragg Gratings. A Bragg Grating is a section of glass that has stripes in it where the refractive index has been changed. Each time the light goes across a boundary between one refractive index and another, a bit is reflected back. If you have enough stripes, the grating acts like a very efficient mirror.
Our pump source is a cheap diode laser. Diode lasers produce messy beams, so they aren't very useful for a lot of the things we want to do. They can also be stacked, so that you get the power from lots of diode lasers being used to pump a single fibre laser with large amounts of power. The problem is that the fibre core is too small for us to focus the low-quality diode laser into it.
To get around this, we focus the pump laser into the much-larger cladding around the core. To contain the pump laser beam, we clad the fibre with an outer sheath. This way, the pump beam bounces around inside the fibre. Every time it crosses the core, a bit more pump light is absorbed.
Now we have everything we need to make a laser: a laser medium, some mirrors to make a laser cavity, and a pump source to excite the electrons. The first reason a fibre laser is useful is because it is stable. When we want to deliver a laser beam, we usually need an optical fibre to move it around safely.
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