High efficiency programmable CGH using DMD generated masks
Abstract
Computer Generated Holograms (CGHs) are used for wavefront shaping and complex optics testing. Present technology allows for recording binary CGHs. We propose a Digital Micro-mirror Device (DMD) as a reconfigurable mask, to record rewritable binary and grayscale CGHs on a photochromic plate. Opaque at rest, this plate becomes transparent when it is illuminated with visible light. We have successfully recorded the very first amplitude grayscale Fresnel CGH, with a contrast greater than 50, which was reconstructed with a high fidelity in shape, intensity, size and location. We propose a new Fourier CGH coding scheme leading to a quantification exceeding 1000 within a smaller cell size of 2x2 pixels. This code has been implemented for the BATMAN-instrument logo for visiting very different spatial frequencies. The CGH is recorded with our DMD-based set-up, leading to a 1000x1000 pixels hologram written on a photochromic plate. The reconstruction of the recorded images with a 632.8nm He-Ne laser beam and an imaging lens leads to images with a perfect fidelity in shape and intensity, for any single pixel of the original object. Our proposed code exhibits a much higher resolution, a better compacity and an increased throughput, in comparison with the current Fourier CGHs. These results reveal the high potential of this method for generating programmable/rewritable CGHs.
- Publication:
-
Holography: Advances and Modern Trends VI
- Pub Date:
- May 2019
- DOI:
- 10.1117/12.2523030
- Bibcode:
- 2019SPIE11030E..0QZ