Fabrication of waveguide spatial light modulators via femtosecond laser micromachining

We have previously introduced an anisotropic leaky-mode modulator as a waveguide-based, acousto-optic solution for spatial light modulation in holographic video display systems. Waveguide fabrication for these and similar surface acoustic wave devices relies on proton exchange of a lithium niobate s...

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Bibliographic Details
Main Authors: Savidis, Nickolaos, Jolly, Sunny, Datta, Bianca, Karydis, Thrasyvoulos, Bove, V. Michael, Jr.
Other Authors: Program in Media Arts and Sciences (Massachusetts Institute of Technology)
Format: Article
Published: SPIE, the International Society of Optical Engineering 2018
Online Access:http://hdl.handle.net/1721.1/116588
https://orcid.org/0000-0002-6937-3740
https://orcid.org/0000-0002-9244-472X
https://orcid.org/0000-0003-2900-4577
https://orcid.org/0000-0001-7148-9665
https://orcid.org/0000-0001-9106-6205
Description
Summary:We have previously introduced an anisotropic leaky-mode modulator as a waveguide-based, acousto-optic solution for spatial light modulation in holographic video display systems. Waveguide fabrication for these and similar surface acoustic wave devices relies on proton exchange of a lithium niobate substrate, which involves the immersion of the substrate in an acid melt. While simple and effective, waveguide depth and index profiles resulting from proton exchange are often non-uniform over the device length or inconsistent between waveguides fabricated at different times using the same melt and annealing parameters. In contrast to proton exchange, direct writing of waveguides has the appeal of simplifying fabrication (as these methods are inherently maskless) and the potential of fine and consistent control over waveguide depth and index profiles. In this paper, we explore femtosecond laser micromachining as an alternative to proton exchange in the fabrication of waveguides for anisotropic leaky-mode modulators.