Innovation and Partnerships Office

Ultra-High Density Diffraction Gratings for Soft X-ray Applications IB-2523


  • Improves spectral resolution of x-ray monochromators and spectrometers
  • Temporal Pulse compression
  • Extreme UV (EUV)
  • Nanotechnology applications requiring ultra-high density periodically alternating lines with different physical or chemical properties
  • Direct self-assembly of nanocrystals or polymers


  • Increases the resolution of soft x-ray spectrometers by two orders of magnitude (resolution of 106)
  • Extremely high diffraction intensity (>40%)
  • Can be manufactured using existing thin film processing techniques
  • Increases intensity of signals with the same resolution


Howard Padmore and colleagues at Berkeley Lab have invented an Ultra-High Density Diffraction Grating that reaches extremely high resolving powers and a technique for fabricating such gratings.   This is the only technology that produces ultra-high diffraction gratings suitable for soft x-ray applications. The researchers   have demonstrated that an extremely high diffraction intensity (>40%) and resolution of 106 are possible. The technology provides a unique way to fabricate a diffraction grating with controllable ultra-high density grooves.

The Berkeley Lab technology employs a combination of precision lithography, anisotropic etching of silicon, multilayer coating, and chemical-mechanical polishing.

How an Ultra-High Density Grating is made: 1) fabrication of a near atomically perfect, low-resolution eschellette grating; 2) deposition of a multilayer coating with alternating materials and nm layer thickness; 3) polishing to reveal the periodic structure with the period determined by the bilayer spacing and slice angle value.

The Berkeley Lab Ultra-High Density Diffraction Grating can be used in spectroscopy as a high resolution, dispersing element and can optimize the intensity, resolution, and size of a spectrometer or monochromator or any combination of the three to a factor of ~30.   More specifically, the Berkeley Lab method can be applied to extreme UV and soft X-ray diffraction up to keV energies.   It can also be used for nanofacet lithography.

The Berkeley Lab technique used to fabricate the Ultra-High Density Grating is useful in constructing linear templates with lines of reactive surfaces.   These templates can then be used to direct self-assembly of nanocrystals or polymers. They can be applied to any application that uses ultra-high density, periodically alternating lines with different properties. This includes temporal pulse compression where a radiation pulse with a broad temporal distribution and chirped in wavelength with respect to time can be compressed to a much shorter pulse.


  • Issued US Patent 8,331,027 available at
  • Available for licensing and collaborative research.


“ALS Scientists Patent Technique to Dramatically Advance Grating-based Spectroscop,” ALS News, Vol. 338, Jan. 30, 2013.


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