New Fourier CGH coding using DMD generated masks

Frederic Zamkotsian; Giorgio Pariani; Patrick Lanzoni; Luca Oggioni; Chiara Bertarelli; Andrea Bianco

doi:10.1117/12.2547970

28 February 2020 New Fourier CGH coding using DMD generated masks

Frederic Zamkotsian, Giorgio Pariani, Patrick Lanzoni, Luca Oggioni, Chiara Bertarelli, Andrea Bianco

Proceedings Volume 11294, Emerging Digital Micromirror Device Based Systems and Applications XII; 112940D (2020) https://doi.org/10.1117/12.2547970
Event: SPIE OPTO, 2020, San Francisco, California, United States

Abstract

Computer Generated Holograms (CGHs) are powerful optical elements used in many fields, such as wavefront shaping, quality testing of complex optics and anti-counterfeiting devices. Lee algorithm is the most used to generate binary amplitude Fourier holograms. Grayscale CGHs are known to give a higher reconstruction quality than binary holograms, but they usually require a cumbersome production process. A very simple and straightforward method of manufacturing rewritable grayscale CGHs is here proposed by taking advantage of two key components: a Digital Micro-mirror Device (DMDs) and a photochromic plate. An innovative algorithm, named Island algorithm, able to generate grayscale amplitude Fourier CGHs, is reported and compared with the standard Lee approach, based on 9 levels. A crucial advantage lies on the fact that the increase or decrease of the quantification does not affect the spatial resolution. In other words, the new coding leads to a higher spatial resolution (for a given CGH size) and a reconstructed image with an order of magnitude higher contrast with respect to the classical Lee-coded hologram. In order to show the large potential of our approach, a 201 levels Island hologram is designed, produced and reconstructed, pushing the contrast to values higher than 10^4. These results reveal the high potential of our process as well as our algorithm for generating programmable grayscale CGHs. Grayscale objects are also studied in order to be produced with our new coding scheme: simulations show a much better reconstruction (resolution, fidelity, contrast) thanks to the quantification of the transparency than the Lee algorithm commonly used.

Citation Download Citation

Frederic Zamkotsian, Giorgio Pariani, Patrick Lanzoni, Luca Oggioni, Chiara Bertarelli, and Andrea Bianco "New Fourier CGH coding using DMD generated masks", Proc. SPIE 11294, Emerging Digital Micromirror Device Based Systems and Applications XII, 112940D (28 February 2020); https://doi.org/10.1117/12.2547970

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available