3D imaging with single exposure on a flat masks

Holographic masks allow to create 3D images of several kinds:

  • Imaging on Piecewise-Flat Surfaces
  • Imaging of 3D volumes
  • Grayscale imaging

Imaging on Piecewise-Flat Surfaces

The holographic mask allows creating a sub-wavelength image on several planes located at distances larger than optical depth of focus (DoF) with a single-mask during a single exposure. [Sub-Wavelength Holographic Lithography (.pdf)]

Other examples:

  • λ=193nm
  • NA=0.7
  • half-pitch: 400nm & 800nm
  • L = 8µm
  • Rayleigh DoF = ±0.34µm
  • λ=355nm
  • NA=0.8
  • half-pitch: 400nm
  • L = 9.6µm
  • Rayleigh DoF = ±0.44µm
  • λ=355nm
  • NA=0.8
  • half-pitch: 200nm & 400nm
  • L = 2.8µm
  • Rayleigh DoF = ±0.44µm

Imaging 3D volumes

Holographic Lithography has promising results in extra deep exposure. It is possible to create vertical channels, which height significantly exceeds the DoF.

Grayscale imaging

SWHL technology allows controlling not only the shape of the aerial image but also its intensity distribution.

With the use of a flat amplitude holographic mask, it is possible to create an array of microlenses of variable aperture and curvature.

  • λ=446.1nm
  • NA=0.24
  • DoF: 50µm
  • Pitch = 100µm
  • Aperture size = 70 - 100 nm
1. Lens shape
2. Sample 25 x 25 lenses.
3. Intensity field distribution
3. Intensity field distribution