An advancement in the fabrication of holographic diffraction gratings has been achieved by a team of researchers, who have successfully developed a large-aperture, high-precision grating using an innovative scanning interference field exposure technique.
Published in Light: Science & Applications, the study showcases the creation of a 1500 mm × 420 mm grating with an exceptionally low wavefront aberration of 0.327λ at 632.8 nm, setting a new standard in grating technology. Led by LI Wenhao from the Changchun Institute of Optics, Fine Mechanics and Physics, the research tackles the longstanding challenge of producing gratings that are both large in size and precise at the nanoscale. The team’s cutting-edge approach integrates high-precision displacement measurement, real-time phase error compensation, and advanced control of interference fringes, enabling the production of seamless, high-quality gratings.
Diffraction gratings are essential components in a wide range of applications, including laser modulation, spectral analysis, and precision displacement measurement. However, traditional fabrication methods have struggled to achieve both large size and high precision simultaneously. The new scanning interference field exposure system developed by the researchers overcomes these limitations by combining grating sensing and laser interferometry for precise displacement measurement, ensuring stability over long exposure times.
The system also employs a dynamic phase-locking model to compensate for phase errors in real time, significantly improving the quality of the interference fringes. By controlling the direction, period, and phase nonlinearity of the fringes, the team achieved a grating with a wavefront gradient of 16.444 nm/cm, making it suitable for demanding applications such as chirped pulse amplification systems and high-energy lasers.
This study not only advances the field of grating fabrication but also opens new possibilities for applications in spectroscopy, laser systems, and ultra-high-precision displacement measurement.
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