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Picosecond Lasers and Traditional Fiber Lasers
To help to understand the core differences for high-end manufacturing, here is a detailed technical comparison between Picosecond Lasers and Traditional Fiber Lasers (which typically operate in the nanosecond range).
1. At a Glance: Key Technical Differences
Technical Feature | Picosecond Laser (Beyond Laser) | Traditional Fiber Laser (Nanosecond) |
Pulse Duration | Trillionths of a second (10^{-12}s) | Billionths of a second (10^{-9}s) |
Processing Method | "Cold" Ablation (Photoacoustic) | Thermal Processing (Photothermal) |
Heat Affected Zone (HAZ) | Minimal to None | Significant |
Peak Power | Extremely High (Megawatts) | Moderate |
Marking Contrast | High-contrast "Matte Black" | Variable / Often Grey or Brown |
Precision | Micron-level (+/- 1um) | Standard (+/- 25-50um) |
2. The Science of "Cold Processing"
The most critical technical difference is how the laser interacts with the material:
Traditional Fiber (Nanosecond): This laser works like a high-speed "torch." The pulse lasts long enough to heat the material to its melting or vaporization point. While effective, the heat spreads to the surrounding area, creating a Heat Affected Zone (HAZ). This can cause micro-cracks, burrs, or material deformation.
Picosecond Laser: The pulse is so fast that the energy is deposited into the material before the atoms have time to vibrate and generate heat.
Instead of melting, the material is instantly "atomized" (turned into gas). This is why it is called Cold Processing. It results in incredibly clean edges with zero thermal damage.
3. Deep Technical Comparison
A. Surface Integrity & Corrosion Resistance
Traditional Fiber: On stainless steel, the heat destroys the "passive layer" (the chromium oxide layer that prevents rust). As a result, fiber-marked parts often fail salt-spray or passivation tests.
Picosecond: Because it avoids heating the surface, the passive layer remains intact. The "black marking" on medical tools is achieved through a nanostructure effect rather than iron oxidation, making it highly corrosion-resistant and permanent even after repeated autoclaving.
B. Peak Power vs. Average Power
Traditional Fiber: Relies on high average power to melt material.
Picosecond: Relies on massive peak power. Because the pulse width is 1000x shorter, the energy density is concentrated into a tiny window, allowing it to mark difficult materials like glass, sapphire, and high-reflective metals (gold/copper) that would reflect or shatter under a traditional fiber laser.
C. Contrast and Aesthetics
Traditional Fiber: Often leaves a "feeling" or texture on the surface. The marks can look different depending on the viewing angle due to light reflection.
Picosecond: Produces a unique matte black finish that is non-reflective and appears the same from every angle. This is the gold standard for luxury branding and medical UDI (Unique Device Identification).
4. When to Choose Which?
Choose Traditional Fiber Laser if:
You are marking standard industrial parts (tags, tools, hardware).
Cost is the primary concern and extreme precision is not required.
You are working with thick metals where deep, rough engraving is acceptable.
Choose Beyond Laser Picosecond Systems if:
Medical/Aerospace: You need marks that survive harsh sterilization or passivation without rusting.
Micro-Electronics: You are marking sensitive chips, wafers, or PCBs where heat could destroy the circuitry.
Fragile Materials: You are working with glass, ceramics, or thin films that easily crack.
High-End Branding: You require a perfect "Impalpable" black finish for consumer electronics (like smartphones) or luxury watches.
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What are the precautions for operating a laser marking machine?
1. It is strictly prohibited to start the laser power supply and Q-switching power supply when there is no water or the water circulation is abnormal.
2. The Q power supply is not allowed to operate without load (i.e., the output terminal of the Q power supply should be left floating).
3. In case of any abnormal phenomenon, first turn off the galvanometer switch and the key switch, and then conduct a check.
4. It is not allowed to start other components before the krypton lamp is lit to prevent high voltage from entering and damaging the components.
5. Pay attention to leaving the output terminal (anode) of the laser power supply suspended to prevent sparking and breakdown with other electrical appliances.
6. Keep the internal circulating water clean. Regularly clean the water tank and replace it with clean deionized water or pure water.
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What should we do when laser intensity decreases and the marking is not clear enough?
1. Turn off the machine and check if the laser resonant cavity has changed; Fine-tune the resonant cavity lens. Make the output light spot the best;
2. The acousto-optic crystal is offset or the output energy of the acousto-optic power supply is too low;
Adjust the position of the audio-visual crystal or increase the working current of the audio-visual power supply;
3. The laser entering the galvanometer deviates from the center: Adjust the laser;
4. If the current is adjusted to around 20A but the light sensitivity is still insufficient: the krypton lamp is aging. Replace it with a new one.
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How to maintain a UV laser cutting machine?
1. It is required to carry out regular cleaning every day, remove debris from the countertop, limiters and guide rails, and spray lubricating oil on the guide rails
2. The waste materials in the collection box should be cleared regularly to prevent excessive waste from blocking the exhaust port.
3. Clean the chiller once every 15 days, drain all the internal water, and then fill it with fresh pure water.
4. The reflector and focusing lens should be wiped with a special cleaning solution every 6 to 8 hours.
When wiping, use a cotton swab or cotton swab dipped in the cleaning solution to wipe from the center to the edge of the focusing lens in a counterclockwise direction.
At the same time, be careful not to scratch the lens.
5. The indoor environment can affect the lifespan of the machine, especially in damp and dusty conditions.
A damp environment is prone to causing rust on the reflective lenses and also easily leading to short circuits, discharge and sparking of the velvet laser.
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What accidents might be caused by the laser emission when using a laser cutting machine?
(1) A fire was caused by the laser coming into contact with flammable materials.
Everyone knows that the power of laser generators is very high, especially when it comes to high-power laser cutting machines, the temperature of the emitted laser is extremely high. The possibility of a fire being caused when a laser beam comes into contact with flammable objects is very high.
(2) Harmful gases may be produced when the machine is in operation.
For instance, when cutting with oxygen, it undergoes a chemical reaction with the cutting material, generating unknown chemical substances or fine particles and other impurities. After being absorbed by the human body, it may cause allergic reactions or discomfort in the lungs and other respiratory tracts. Protective measures should be taken when conducting work.
(3) Direct laser exposure to the human body can be harmful.
The damage caused by lasers to the human body mainly includes damage to the eyes and skin. Among the harms caused by lasers, the damage to the eyes is the most severe. Moreover, damage to the eyes is permanent. So when doing homework, you must pay attention to protecting your eyes.
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What is the focused spot diameter of nanosecond, picosecond and femtosecond laser?
Nanosecond: The light spot is 0.5-1mm.
Picosecond: The focused spot is around 0.02mm.
Femtosecond: Under the action of a laser beam with a high repetition rate of 100-200KHz and a very short pulse width of 10ps,
the focused spot diameter is as small as 0.003mm.
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What are the main applications of UV laser cutting machine?
The UV laser cutting machine can be used for cutting and depaneling PCB.
It can precisely cut and shape various types of PCB circuit boards with V-CUT and stamp holes, and open Windows and covers.
It can also be used for separating packaged circuit boards and ordinary smooth boards.
It is suitable for cutting various types of PCB substrates, such as ceramic substrates, rigid-flex boards, FR4, PCBs, FPCs, fingerprint recognition modules, cover films, composite materials, copper substrates, aluminum substrates, etc.
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Precautions for laser cutting machines to process various metal materials?
Copper and brass:
Both materials have high reflectivity and excellent thermal conductivity.
Brass with a thickness of less than 1mm can be processed by nitrogen laser cutting.
Copper with a thickness of less than 2mm can be cut. The gas used for laser cutting processing must be oxygen.
Copper and brass can only be cut when a "reflective absorption" device is installed on the system. Otherwise, reflection will damage the optical components.
Synthetic materials:
Processable synthetic materials include: thermoplastics, thermosetting materials and artificial rubber.
Aluminum:
Despite its high reflectivity and thermal conductivity, aluminum materials with a thickness of less than 6mm can be cut, depending on the type of alloy and the capacity of the laser.
When cutting with oxygen, the cutting surface is rough and hard.
When nitrogen is used, the cutting surface is smooth.
Pure aluminum is extremely difficult to cut due to its high purity.
Only when a "reflection and absorption" device is installed on the fiber laser cutting machine system can aluminum materials be cut.
Otherwise, reflection will damage the optical components
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What should be paid attention to when laser cutting stainless steel?
Laser cutting processing of stainless steel requires the use of oxygen, under the condition that edge oxidation is not a concern.
If nitrogen is used to achieve an edge free of oxidation and burrs, no further processing is required.
Coating an oil film on the surface of the sheet will achieve a better perforation effect without reducing the processing quality.