When we talk about LASERS, we must keep in mind three macroscopic measurement parameters:
- Frequency (or rather the number of pulses in relation to a length of time) -> kHz
- Power -> W
- Speed -> mm/s (or px/s)
Laser pulses are usually fixed: with standard fiber lasers, a pulse has duration of about 120 ns, while the pulse frequency varies from 20 to 100 kHz.
Instead, with MOPA lasers, pulse duration varies and can be set in a range from 4 to 200 ns, with a frequency ranging from 20 kHz to 1 MHz. The short pulse is especially useful for marking on plastics, as it prevents burning the material by avoiding direct contact.
What is the difference between a MOPA laser machine and a Fiber Optic laser?
A frequent question from our clients, they ask what the main difference between these two technologies is, is it just color engraving on some materials? Why is the MOPA laser more expensive? What materials can these technologies record? This and other questions will finally get an answer in this blog about MOPA and Fiber Optic Laser.
Internally they are different.
Even if these two machines at a glance look very similar or the same, inside, they work differently. Fiber laser machines use a technology called Q-Switched that allows the power source to generate frequencies between 1 and 500 kHz.
On the other hand, the Master Oscillator Power Amplifier, known as MOPA, works differently with its power source, this allows the machine to have a pulse frequency with more amplitude than fiber, from 1 to 2700 kHz. This allows the MOPA laser to have different engraving results on some plastic and metallic materials compared to the engraving results of Q-Switched technology or fiber-optic laser.
Even though it is not a new technology, this type of MOPA technology is far from the high engraving speed that the fiber laser can achieve. Color engraving with the MOPA laser is actually not fast, and this is something to expect if you are looking to engrave thousands of metal parts a day with colorful logos. The truth is that color engraving is not fast and can be slow, depending on the design you choose and how many colors you want to engrave.
On the other hand, fiber or Q-Switched laser machines have a better engraving speed, and although they cannot engrave colors, if you want to engrave metals without colors, this technology can engrave at high speeds.
What are the benefits of a variable pulse?
The MOPA laser maintains the benefits of traditional Fiber (no maintenance, long life, and air cooling) but can boast a number of added values for marking both plastics and metals.
The initial drawback of this technology could be its price, but the difference with a traditional fiber is so minimal that it is largely compensated by its application flexibility.
However, it is worth specifying that, if we have to mark natural aluminum or die-cast products, a traditional fiber laser may be sufficient to achieve high-quality results.
Suitable materials for fiber laser.
Fiber machines can be used for laser engraving of metals and various plastics such as ABS. Think of materials like:
- Metals: Steel, iron, stainless steel, aluminum (anodized), copper, bronze, gold, silver, platinum.
- Plastic like ABS
- Synthetic leather mirrors.
Fine silver can be cut with a fiber laser. Ask about the possibilities.
When is it worth using?
- Laser marking on metals and plastics
- Colored laser marking
- Marking with the coating process
Conclusions Both machines can do similar jobs; however, if you are looking for a better finish on plastic materials and have the possibility of engraving different colors on stainless steel, or titanium, you can think of the solution that the MOPA laser can offer. On the other hand, if you are just looking to engrave metals at high speed and don’t need to engrave colors on metals, you can choose a fiber optic laser. These machines may look the same, but they are different not only in work effect and technology but they are also very different in price, MOPA laser technology also tends to be much more expensive than normal Q-fiber optic lasers.