Sapphire Processing

Machining transparent fragile materials is one of the main interests for picosecond laser systems. Nonlinear absorption at high peak powers of picosecond pulses along with none-thermal ablation characteristic of ultra-short pulses can produce crack-free clean cut lines on such materials.

Cutting sapphire crystal is of high interest for different applications such as cell phone industries, microelectronic devices and infrared optical components. The remarkable hardness of sapphire, in addition to the transparency of the crystal, makes it difficult to perform a clean and precise cut with economical efficiency.

Here we present some features of sapphire cutting experiments that have been conducted in the Applications Development Lab at Attodyne. Clicking on each image will enlarge it. Precision in conveying the capability of our technology is important to us. Hence the samples are not cleaned after they are cut and before being photographed.

Microscope images of the cut edges on the flat line on a 0.75m thick sapphire sample. Left image shows the top surface and right one shows the bottom surface. The sapphire piece is in the right side in both images.

Different angles for a cut on a 0.75mm thick piece of sapphire. The linear cutting speed for this piece is 0.77mm/min.W.

Microscope images of the curved edges on a 0.3m thick sapphire sample. Left image shows the top surface and right one shows the bottom surface. The sapphire piece is in the left side in both images.

These pieces have a dimension of 8x8mm with the inner circle of 4mm diameter.

Several pieces cut from a single piece of 0.3mm sapphire wafer. Note that although pieces are very close to each other, there is no sign of crack in the wafer. The linear cutting speed for this piece is 2.224mm/min.W.