All You May Want to Know about Laser Etching

Recent advancements in laser technology have made laser etching more accessible to small businesses and craftsmen. This technique is similar to laser engraving but with its own key features that give it an edge over other laser marking techniques.

If you’re interested in this technique, OMTech is here to teach you all the basics. By the end of this read, you will gain some valuable knowledge about laser etching. Let’s dive in!

What is Laser Etching All About?

Simply put, it is a marking process carried out by melting only the surface of the workpiece, creating a visible contrast in texture. The laser beam must deliver a high amount of energy capable of melting the exterior. The result is either a black, white, or gray-colored mark. It’s renowned for its versatility in metals and glass applications that has become synonymous with producing logos, barcodes, serial numbers, and other permanent markings.

Technically speaking, this technique utilizes pulsed laser beams that are more distant from one another than in engraving. Quantitatively, a 100W pulsed laser produces up to 100,000 pulses per second, where each pulse can release up to 1 millijoule of energy.

When Did Laser Etching Start?

There isn't an exact date traced back to this specifically. However, history tells us it began around the same time as laser engraving, which started around 1978. Nonetheless, some notable events marked the evolution of this technique:

1960 marked the first laser constructed, which used ruby crystal as its medium of amplifying light. That same year witnessed the invention and demonstration of the continuous laser beam. 1962 brought us Q-switching technology to produce a pulsed laser beam, which is still used in laser etchers and engravers today. Then, in 1964 the CO2 laser tube was invented. Fast forward to 1996, and the first software designed for laser engraving and etching was developed, ushering in the modern era of this science.

What is the Working Principle of Laser Etchers?

As mentioned earlier, the focus here is mostly on glass, but it is still similar to other materials. For glass laser etching, it occurs at specific frequencies, and this distinguishes it from different materials. Recall that frequency is linked to wavelength, and wavelength determines the depth the laser can penetrate to cut, engrave, or etch. This technique can produce an image, logo, text, or specific pattern on the glass material. 

To understand how this technique works on glass, you must know that glass is made from sand. Air and water get trapped in the melted sand. Low-power CO2 laser light is the most appropriate for marking natural materials like sand. This technique starts when a laser beam hits the glass, and the base material (sand) gets heated up to a specific temperature. The laser beam attacks the trapped air and water in the glass, making microscopic surface fractures, which leave room for tiny chippings to dissociate and create a contrast with the untouched surface.

Note that a low-power CO2 laser light produces the right frequency needed for glass etching. While you can laser etch on metals, it requires a very high frequency to penetrate them.  

Which Materials are Suitable for Laser Etching?

This technique is suitable for metals such as steel, aluminum, magnesium, zinc, lead, and stainless steel. Non-metals like wood, foam, leather, ceramics, rubber, glass, and plastic can also be etched for permanent marking. Glass products such as pint glasses, wine bottles, and crystal glass are popular applications for etching. However, the wonders of glass etching do not stop there; the possibilities for you and your machine are endless.

What Colors Can Laser Etching Produce?

The best color that this technique produces is black and white, but it can also produce gray shades. As the laser beam hits the surface, light ray diffusion creates a black color. On the other hand, if the material absorbs the light rays, then a white color is formed. Generally, the extent of the surface roughness determines whether the light is absorbed or diffused.

When laser etching metals with a MOPA fiber laser, you can achieve colorful marking results.

The Benefits of Opting for Laser Etching

• Speed

Etching is rapid to mark; in fact, it is more than twice as fast as engraving. This efficiency helps you etch more in less time. However, you also have to adjust your machine’s etching speed to match your target material and etching depth (the slower the speed, the greater the laser beam penetrates).

• Precision and Accuracy

It is highly precise and accurate, which makes it suitable for thin and fragile materials. Studies have shown that it can mark as low as 0.001" in depth.

• Durability

It is generally cost-effective, durable, and versatile.

• Material saving

It is a non-contact process, so you can minimize material waste and maximize savings.

What Type of Laser Machines Can Etch?

Well, this depends on the material in question. The nature of the material determines how much frequency is needed to properly penetrate it and achieve a permanent marking. Given this, both the fiber laser machine and CO2 laser machine can conveniently produce this effect. Ideally, fiber laser machines will penetrate metals only and other materials that require high frequency. On the other hand, CO2 laser machines will penetrate glass, wood, and other low-frequency materials. Remember that you would need specialized rotary accessories for your laser machines to etch cylindrical objects such as cups, bottles, etc.

Final Thoughts

Remember that glass is the ideal material for laser etching applications. If you have any questions or want to see some of our user's work online, feel free to explore our social media platforms like Instagram.

OMTech is always available to cater to all your laser machine needs. We recently opened our walk-in showroom in Southern California, where you can see our machines in action. We’re excited to now offer expert demonstrations and insider knowledge in person!