Programmable CGH on photochromic material using DMD generated masks

Date Issued
2018
Author(s)
Alata, Romain
•
Zamkotsian, Frédéric
•
Lanzoni, Patrick
•
•
•
Bertarelli, Chiara
DOI
Abstract
Computer Generated Holograms (CGHs) are used for wavefront shaping and complex optics testing, including aspherical and free-form optics. Today, CGHs are recorded directly with a laser or intermediate masks, allowing only the realization of binary CGHs; they are efficient but can reconstruct only pixilated images. We propose a Digital Micromirror Device (DMD) as a reconfigurable mask, to record rewritable binary and grayscale CGHs on a photochromic plate. The DMD is composed of 2048x1080 individually controllable micro-mirrors, with a pitch of 13.68 μm. This is a real-time reconfigurable mask, perfect for recording CGHs. The photochromic plate is opaque at rest and becomes transparent when it is illuminated with visible light of suitable wavelength. We have successfully recorded the very first amplitude grayscale CGH, in equally spaced levels, so called stepped CGH. We recorded up to 1000x1000 pixels CGHs with a contrast greater than 50, using Fresnel as well as Fourier coding scheme. Fresnel's CGH are obtained by calculating the inverse Fresnel transform of the original image at a given focus, ranging from 50cm to 2m. The reconstruction of the recorded images with a 632.8nm He-Ne laser beam leads to images with a high fidelity in shape, intensity, size and location. These results reveal the high potential of this method for generating programmable/rewritable grayscale CGHs, which combine DMDs and photochromic substrates.
Coverage
Emerging Digital Micromirror Device Based Systems and Applications X
All editors
Douglass, Michael R.; Lee, Benjamin L.
Series
Volume
10546
Start page
1054606-1
Conferenece
Emerging Digital Micromirror Device Based Systems and Applications X
Conferenece place
San Francisco, California
Conferenece date
27 January - 1 February, 2018
Uri
Url
Issn Identifier
0277-786X
Ads BibCode
2018SPIE10546E..06A
Rights
open.access
File(s)
Loading...
Thumbnail Image
Name

C61.pdf

Description
Pdf editoriale
Size

1.86 MB

Format

Adobe PDF

Checksum (MD5)

7504131da3da5ea428125286015e4609