It is a frequent question from our customers, they wonder what is the main difference, it is only the color engraving over some materials? Why MOPA laser it's more expensive? Which materials can these technologies engrave? These and other questions will finally get an answer in this blog about MOPA and Fiber Lasers.
Different inside technology
Even if these two machines have a very similar or same outlook, inside, they work differently. The fiber laser machines use a technology called Q-switched that allows the power supplier to generate the path light only between 1 to 500 kHz.
On the other hand, the Master Oscillator Power Amplifier most know as MOPA generate the power source with a different method, and this allows the machine has a pulse frequency with more amplitude than the fiber, from 1 to 4000 kHz. These enable the MOPA laser to have different engraving results over some plastics and metal materials in comparison of the Q-switched or fiber laser technology.
Which materials can these machines engrave?
MOPA Laser
This machine can engrave over:
- Gold
- Aluminium (with dark color effect also)
- Stainless Steel (with multiple colors)
- Platinum
- Silver
- Titanium
- Brass
- Tungsten
- Carbide
- Nickel
- Carbon steel
- Crome
- Copper
- Iron and other metals
- ABS plastic (low rate of melting burn)
- PC plastic (low rate of melting burn)
- PLA plastic
- Silicon plastic
- PBT plastic and others
Fiber Laser or Q-switched
This machine can engrave over:
- Gold
- Aluminium
- Stainless Steel (Only white and dark colors)
- Platinum
- Silver
- Titanium
- Brass
- Tungsten
- Carbide
- Nickel
- Carbon steel
- Crome
- Copper
- Iron and other metals
- ABS plastic (high rate of melting burn)
- PC plastic (high rate of melting burn)
- PLA plastic
- Silicon plastic
- PBT plastic and others
These machine can engrave different plastics but in some of them you will feel the engraving by the touch of our fingers.
MOPA Laser still on develop
This technology is not new but still is far away from the high speed of engraving that Fiber laser can reach. The color engraving with the actual MOPA laser isn't fast and this is something you should expect if you are looking for engrave thousand of metal pieces a day with colorful logos. The true is that the color engraving is not fast and can be slow depending of the marking you chose and the quantity of colors you want to engrave.
On the other hand the fiber laser or Q switched machines have a better rate of engraving speed over some plastics and over some metal materials.
Video Shoot at normal speed.
In conclusion both machines can do similar works, however, if you are looking for a better finishing on plastic materials and for having the possibility of engraving different colors on stainless steel, titanium or black color on aluminum you can think about the solution that MOPA laser can offer. On the other hand, if you are only looking for engrave metals at high speed, deepness, and you don't need to engrave colors on metals, then you can choose a fiber laser. these machines may look the same but they are different not only on work effect and technology, they are also very different on price, MOPA laser technology also tends to be expensive than normal Fiber Q-switched lasers. For more information get in contact with us.
Write a comment
Sander (Monday, 14 December 2020 00:41)
Hi there,
I just saw your Mopa laser YT video.
This video made me very curious to know more about the corrosion of the colors.
Could you give me more information about how and why this is happening and most importantly how to possibly prevent or protect the colors from corrosion?
Kind regards
Sander
Farook (Monday, 01 March 2021 11:10)
Mopa fibre laser
Eduardo de la (Friday, 02 April 2021 07:02)
I need engrave some metals (brass AND Steel deep) AND stainless Steel curved surface. UV ir MOPA can I use? Regards edecalho@gmail.com
Dave Aker (Wednesday, 29 September 2021 17:30)
Nice article, I like how it doesn't promise that every laser will do everything you want it to.
Nearly every article I read about laser tech written the past 3-4 years promises the world and has conflicts with other articles from the same time period. Unfortunately, the subject is about as clear as mud as of late 2021 (but this article attempts to add clarity, I like that).
I also like that this article cautions lengthy cycle times for non-porous, black surface marks on SS using a carbon migration technique that the laser marking industry calls 'annealing' (despite it not really being an annealing process). [dark anneal marks are also regularly repeatable on carbon steel and titanium alloys in a full manufacturing production environment; but yes, they are much slower to create than deep engravings]. I understand that annealing can be faster when combining higher powered lasers with larger lenses that increase spot diameter while maintaining the appropriate energy concentration needed for annealing... but I just heard that from a sales guy (we haven't tried it on our 60W system yet).
Also, the article clearly states that color changing SS, Carbon Steel, and Titanium via the 'anneal' technique is possible but not highly repeatable (kudos!!!). I've had limited success with color techniques using a high-end 20W MOPA Fiber Laser [built in 2018; ~$27k larger format system] and learned that color changing is more of an artistic demonstration of skill that requires an unlimited amount of time and resources to achieve occasional success than a viable, repeatable production process for industrial manufacturing.
I'm not a historian on laser tech but I believe that most modern (as of 2021) pulsed marking lasers operating in the 1063nm spectrum (that are not CO2 lasers with unpulsed, continuous waveforms) are called either q-switched fiber or MOPA fiber lasers (ok, there are some spelling inconsistencies with 'fiber' vs 'fibre' but that's 'getting into the weeds'). I wonder if there was an iteration of lasing tech that paired a MOPA source with a non-fiber gain medium at some point... if there was, it must not have been that popular (I think this is the only article I've read that separates MOPA from Fiber but there are probably others out there that do).
Regardless, I have few issues rapidly achieving deep engravings with the 20W MOPA Fiber Laser on aluminum and softer metals but it can be relatively slow (for a production environment) when hitting a 0.006" deep serial number spec on steel and SS substrates (it'll get there, just takes 3x as long as our newer 60W MOPA Fiber Laser system).
To 'Eduardo de la': Marking a curved surface depends largely upon your base setup. We use galvo systems with fixed marking heads that steer a wide beam of laser light with tiny mirrors through a focal lens to produce a concentrated spot of energy on the substrate (about 10mm diameter beam focused down to a spot ~40 microns in diameter). The lenses in a galvo system provide 'focal forgiveness' which allows marking around part of the circumference of the cylindrical object (+/- about 1mm for a small lens, more forgiveness with a larger lens) because the energy concentration is still high enough that far outside of the ideal focal range to effectively lase many materials (especially polymers and soft metals). Always check your test piece for image distortion before moving on to full production, wrapping a flat vector graphic about a cylinder can stretch it at the extents a bit. To determine wrap I can achieve on an object, i usually draw a long rectangle in Minilase Pro SE (the software we use has basic object drawing capabilities) and position it perpendicular to the cylinder and mark with laser settings that I anticipate using for the final mark. The test run will not mark at the beginning of the cycle where the rectangle is clearly outside of the effective focal range but it will start engraving as it approaches the center of the cylinder (poorly at first), then i'll get good marking action in the central portion, then poorly again, then no marking again. The band of good engraving shows about how far around the object I can wrap a mark without using a rotational motion device. That said, you can always use a programmable rotary device (I use one for marks that need to wrap longer than what i can achieve via focal forgiveness). Unfortunately, if you're using a gantry style laser (one where the laser head moves on an x-y table, like a cnc machine), I have no experienced advice for you because I have not used one in practice (you may need a programmable rotary device from the laser manufacturer; i understand that many for gantry systems are proprietary hardware). I hope this helps!
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