- Wed Jul 28, 2010 12:25 am
#327607
Here's my new toy. Sub-Surface Laser Engraving (SSLE)
Sub-surface laser engraving is the process of engraving an image below the surface of a solid material, usually glass, with an optical clarity to minimize distortion of the laser.
Since its inception in the late 1990s, SSLE has become more cost effective with a number of different sized machines ranging from small (~US$35,000–60,000) to large production sized tables (>US$250,000). Although these machines are becoming more available, it is estimated that only a few hundred are in operation worldwide. Many machines require very expensive cooling, maintenance and calibration for proper use. The laser diode, the primary component which excites a pulsed solid state laser, can easily cost one third of the machine itself and functions for a limited number of hours.
In past 5 years the use of SSLE has become more cost effective to produce 3D images in souvenir 'crystal' or promotional items with only a few designers concentrating on designs incorporating large or monolithic sized crystal. A number of companies offer custom made souvenirs by taking 3D pictures or photos and engraving them into the crystal. Quality of the designs and images varies greatly between vendors in the promotional and personal services sector (photo engravers) – the mass producing curio vendors have the habit of reducing resolution of the points and lowering output to maximize their laser diode's lifespan.
A type of Laser known as the Q-switched beam laser was developed in the late 1960’s that generates a pulsed laser beam. Each pulse carries a very high amount of energy. These high energy lasers, however, are problematic. The pulsed beams need to be manipulated, focused, and directed with glass optics. Laser optics needed to be meticulously clean and free of impurities or the beam energy would crack the glass of a lens or mirror. The study of Laser induced damage in optics became in itself a major area of study for Physics researchers, and international meetings of scientists were held each year to share and publish their research. As a by product of this research effort, it was discovered that the damage was sometimes completely contained within the glass optics (thus the birth of our specialized engraving within crystal awards and promotional items, crystal paperweights and crystal recogniton awards and more). What has been learned in the years of study since the initial discovery of this phenomena is that if a laser is focused into optical glass, at some threshold level of energy a portion of the glass can transition from its solid state, and skipping both the liquid and gas states, it becomes a plasma, the fourth state of matter. The flash of lightning is the formation of a plasma from the air that happens to be in the way of the beam of energy from the storm to the surface of the planet. This happens inside glass as well, and has caused decades of headaches for laser physicists. The plasma sparks expanded inside the glass, and caused numerous types of damage. Laser damage in optics continues to be an active area of academic research.
Dr. R. Marc Clement is a Laser Physicist and professor at the University of Swansea in the UK. In the late 1980’s, Dr. Clement worked with United Distillers and Vintners, now Diageo, on an unusual project. United Distillers was facing an increasing problem of counterfeit liquors, particularly on the international market. Certain labels of Scotch produced by United Distillers, such as Johnny Walker Blue Label, sell for hundreds of British pounds per liter.
The Invention of Controlled Subsurface Marking
Dr. Clement’s proposed solution to the problem was to mark the liquor bottles inside the glass by causing controlled points of laser induced subsurface damage within the glass. The “novelty” or inventive step of the invention was the ability to control the location of the mark in three dimensions well enough to create a defined series of points which could form a detectible and identifiable mark. The patent teaches a method for doing this and the claims cover virtually all forms of subsurface laser engraving used in our industry. In 1991 Dr. Clement filed a patent application in the US disclosing the invention and requesting patent rights. The US patent office granted the patent and claims in 1993.
... or, in short:
Sub-surface laser engraving is the process of engraving an image below the surface of a solid material, usually glass, with an optical clarity to minimize distortion of the laser.
Since its inception in the late 1990s, SSLE has become more cost effective with a number of different sized machines ranging from small (~US$35,000–60,000) to large production sized tables (>US$250,000). Although these machines are becoming more available, it is estimated that only a few hundred are in operation worldwide. Many machines require very expensive cooling, maintenance and calibration for proper use. The laser diode, the primary component which excites a pulsed solid state laser, can easily cost one third of the machine itself and functions for a limited number of hours.
In past 5 years the use of SSLE has become more cost effective to produce 3D images in souvenir 'crystal' or promotional items with only a few designers concentrating on designs incorporating large or monolithic sized crystal. A number of companies offer custom made souvenirs by taking 3D pictures or photos and engraving them into the crystal. Quality of the designs and images varies greatly between vendors in the promotional and personal services sector (photo engravers) – the mass producing curio vendors have the habit of reducing resolution of the points and lowering output to maximize their laser diode's lifespan.
A type of Laser known as the Q-switched beam laser was developed in the late 1960’s that generates a pulsed laser beam. Each pulse carries a very high amount of energy. These high energy lasers, however, are problematic. The pulsed beams need to be manipulated, focused, and directed with glass optics. Laser optics needed to be meticulously clean and free of impurities or the beam energy would crack the glass of a lens or mirror. The study of Laser induced damage in optics became in itself a major area of study for Physics researchers, and international meetings of scientists were held each year to share and publish their research. As a by product of this research effort, it was discovered that the damage was sometimes completely contained within the glass optics (thus the birth of our specialized engraving within crystal awards and promotional items, crystal paperweights and crystal recogniton awards and more). What has been learned in the years of study since the initial discovery of this phenomena is that if a laser is focused into optical glass, at some threshold level of energy a portion of the glass can transition from its solid state, and skipping both the liquid and gas states, it becomes a plasma, the fourth state of matter. The flash of lightning is the formation of a plasma from the air that happens to be in the way of the beam of energy from the storm to the surface of the planet. This happens inside glass as well, and has caused decades of headaches for laser physicists. The plasma sparks expanded inside the glass, and caused numerous types of damage. Laser damage in optics continues to be an active area of academic research.
Dr. R. Marc Clement is a Laser Physicist and professor at the University of Swansea in the UK. In the late 1980’s, Dr. Clement worked with United Distillers and Vintners, now Diageo, on an unusual project. United Distillers was facing an increasing problem of counterfeit liquors, particularly on the international market. Certain labels of Scotch produced by United Distillers, such as Johnny Walker Blue Label, sell for hundreds of British pounds per liter.
The Invention of Controlled Subsurface Marking
Dr. Clement’s proposed solution to the problem was to mark the liquor bottles inside the glass by causing controlled points of laser induced subsurface damage within the glass. The “novelty” or inventive step of the invention was the ability to control the location of the mark in three dimensions well enough to create a defined series of points which could form a detectible and identifiable mark. The patent teaches a method for doing this and the claims cover virtually all forms of subsurface laser engraving used in our industry. In 1991 Dr. Clement filed a patent application in the US disclosing the invention and requesting patent rights. The US patent office granted the patent and claims in 1993.
... or, in short:
Next Limit Team
- By CDRDA
