When cutting glass with a CO₂ laser, the best “laser only” applications are typically thin glass substrates in the range of 30 to 600 microns (0.0012” – 0.0236”) thick. Without using specialized, and in some cases, proprietary processes, thicker types of soda-lime (float) glass are difficult to laser cut in one step.

Fortunately, the exceptions to the rule are these stained glass samples that cut very well using a Synrad sealed-CO₂ laser. As with standard float glass, straight-line cutting of stained glass is easily done by scoring and snapping. The difficulty, as any stained glass artist will tell you, is in creating irregular shapes. Traditionally, curved shapes are made by nibbling away at the contour, by grinding on a diamond wheel, or by cutting using a diamond-bladed bandsaw – all being time- and labor-intensive processes.

Our cutting setup for these opaque and translucent stained glass samples consisted of a Firestar f400 laser with beam delivery provided by an XY “flying optics” system. Beam focus was through a 2.5” positive meniscus lens that provides a 100-micron (0.004”) spot with a 1.8 mm (0.07”) depth of focus.

In addition to creating the brilliant hues and colors seen in stained glass, the addition of metallic oxides or metallic salts to the glass formulation appears to alter the glass structure so that the laser’s intense, localized heating does not lead to unintended thermal fracturing of the glass substrate. Cut edges exhibit the same type of striation patterns seen in metal cutting where vaporized and molten material is blown through the cut area by a high-pressure assist gas.