Lensless computer-generated hologram with wavelength-order resolution consisting of photon sieves

Abstract

We propose a photon-sieve hologram (PSH), a novel computer-generated hologram for generating an image with a resolution of the order of the wavelength. The PSH is designed by synthesising many photon sieves. The PSH has a simple structure that consists of pinholes with the same sizes and depths, and it directly generates images without other optical elements such as masks and imaging optical system. It is advantageous for image generation in ultraviolet and x-ray bands, where high-transmittance and high-numerical-aperture optical systems are difficult to build. In this study, we introduce a sparse photon sieve to configure the PSH and describe the principle of image generation and design procedure. We also fabricate PSHs that generate a line image and a broken-line image to demonstrate phase controllability, and skew images for three-dimensional image generation.

Optimal design of photon-sieve holograms for fine-line image generation

“…As d m increases, a m decreases. This relationship is described in [20]. All the diameters of the pinholes on the PSH are equal.…”

“…Photon-sieve holograms (PSHs) have been used to obtain high-resolution images with a CGH alone, i.e. without the use of reducing projection optics [20]. This CGH is designed using the point-source method or point-cloud method [21][22][23][24][25].…”

“…We previously designed a PSH that projected a straight-line image by arranging spots on a straight line [20]. However, in the images obtained via numerical simulation and experiment, the intensity of the line image was uneven.…”