This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: More than just a precious gemstone for jewelry, diamond has properties that make it attractive for several next-generation, high-performance technologies. Its high thermal conductivity can help move heat away from semiconductor devices, while its wide bandgap is promising for high-power electronics.
Moreover, its transparency in the visible light range makes diamond useful for demanding optical applications. Unfortunately, the extreme hardness, so characteristic of diamond, also makes it hard to turn into the thin, precisely shaped substrates that these technologies need. Over the past few years, laser-based diamond slicing has emerged as a potential alternative to conventional mechanical machining.
Simply put, focused lasers can produce microscopic structural modifications directly inside the crystal, leading to internal stresses that promote and guide crack propagation. However, scientists still don't fully understand how diamonds produced via different methods respond to such laser treatment. In a recent study, published in the journal Diamond and Related Materials on Nov. 1, 2026, a research team led by professor Hirofumi Hidai from the Graduate School of Engineering, Chiba University, Japan, set out to address these knowledge gaps.
Their paper, coauthored by Mahiro Ikeno from Chiba University, investigates how different lab-grown diamonds respond to ultrashort laser pulses, turning these insights into a practical strategy to slice large diamonds. The team first compared three single-crystal diamonds, one made by the high-pressure high-temperature (HPHT) method and two via chemical vapor deposition (CVD), each with a different level of nitrogen impurity. They irradiated these samples with focused laser pulses, with pulse durations varying from 233 fs to 30 ps.
They then used optical microscopy, spectroscopy and image analysis to examine the size, shape and continuity of the modified regions produced inside each diamond. The diamond samples responded quite differently to the laser pulses. The two CVD diamonds could be modified using much shorter pulses than the HPHT diamond.
Additionally, in the CVD diamonds, the shortest pulses produced tiny, separated marks, whereas pulses of about 10 ps or longer produced more continuous modified regions. Nitrogen content alone did not explain the differences observed between samples, suggesting that differences in microscopic defects associated with the crystals' individual growth histories may play an important role. Compared with HPHT diamonds, CVD diamonds also tended to exhibit less stable laser-induced modified regions, as well as greater variation in their morphology.
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