Ultrashort laser pulses can slice lab-grown diamond along useful crystal plane

Scientists have found a novel approach to slicing lab-grown diamond into usable shapes for advanced technologies. Diamond's exceptional properties make it ideal for high-performance applications, but its extreme hardness poses challenges in manufacturing. Researchers at Chiba University in Japan investigated how different diamond production methods respond to ultrashort laser pulses.

They compared three single-crystal diamonds - one created via high-pressure high-temperature (HPHT) and two via chemical vapor deposition (CVD) - with varying nitrogen impurities. When exposed to focused laser pulses of durations ranging from 233 fs to 30 ps, the CVD diamonds reacted differently compared to the HPHT diamond. Shorter pulses worked better for CVD diamonds, creating distinct, separated marks, while longer pulses produced continuous modifications.

Nitrogen content alone didn't account for these differences, suggesting microscopic defects from each crystal's unique growth history played a role. Using 10 ps pulses, the researchers sliced an 8 mm x 8 mm CVD diamond along the {100} plane, the easiest plane to polish, after four processing steps. The resulting diamond slice was about 710 times larger than a previous HPHT diamond slice produced.

This technique could pave the way for creating larger diamond substrates for optical components, electronics, and power semiconductors. The scalable process could reduce manufacturing costs and improve material utilization, potentially accelerating the adoption of diamond in various high-tech industries.