Type 1 diabetes is caused by an insufficient production of the hormone insulin by cells in the pancreas called beta cells and estimated to affect 9.5 million people worldwide. Low insulin levels allow glucose levels to remain elevated, which in the long term can damage organs such as the kidneys, the eyes, and the cardiovascular system. People with diabetes require lifelong monitoring of blood sugar levels coupled with insulin injections to keep blood sugar levels at a stable, healthy level.

A potential new treatment option for those patients is the replacement of lost or dysfunctional pancreatic beta cells, either by cell transplantation, or by the generation of new beta cells from existing cells within the body. This latter strategy was pursued by the team of Xiaofeng Huang from Weill Cornell Medicine, USA and Qing Xia from Peking University, China who previously discovered that cells in the mouse stomach can be transformed into pancreatic beta cells by genetic engineering.

The research group led by Prof. Young-Jin Kim has demonstrated a nanometer-resolution displacement sensing methodology by actively modulating deep-UV beams generated via third-harmonic conversion of an 800 nm femtosecond laser. Instead of manipulating the deep-UV beam directly, the fundamental near-IR beam was pre-modulated and its phase profile was coherently transferred to the generated deep-UV harmonic, enabling stable and real-time control in an absorption-dominated wavelength region where conventional modulators do not operate. The team further realized high-visibility periodic beam patterns and tuned their pitch and orientation to induce moiré amplification against semiconductor periodic patterns, detecting displacement signals that were invisible to direct optical imaging. The demonstration provides a first practical route to active beam modulation-based precision metrology in the deep-UV band and is expected to extend toward EUV and X-ray regimes for future 3 nm node linewidth metrology, attosecond science, and real-time bio-imaging applications. This study has been published in PhotoniX (Q1, IF 19.1) on November 6 and supported by the National Research Foundation of Korea.