Shapeshifting Diffractive Optical Devices

Author(s):

Oscurato, Stefano L.; Reda, Francesco; Salvatore, Marcella; Borbone, Fabio; Maddalena, Pasqualino & Ambrosio, Antonio

Abstract:

“In optical devices like diffraction gratings and Fresnel lenses, light wavefront is engineered through the structuring of device surface morphology, within thicknesses comparable to the light wavelength. Fabrication of such diffractive optical elements involves highly accurate multistep lithographic processes that in fact set into stone both the surface morphology and optical functionality, resulting in intrinsically static devices. In this work, this fundamental limitation is overcome by introducing shapeshifting diffractive optical elements directly written on an erasable photoresponsive material, whose morphology can be changed in real time to provide different on-demand optical functionalities. First a lithographic configuration that allows writing/erasing cycles of aligned optical elements directly in the light path is developed. Then, the realization of complex diffractive gratings with arbitrary combinations of grating vectors is shown. Finally, a shapeshifting diffractive lens that is reconfigured in the light-path in order to change the imaging parameters of an optical system is demonstrated. The approach leapfrogs the state-of-the-art realization of optical Fourier surfaces by adding on-demand reconfiguration to the potential use in emerging areas in photonics, like transformation and planar optics.”

Link to Publications Page

Publication: Laser &ampmathsemicolon Photonics Reviews
Issue/Year: Laser &ampmathsemicolon Photonics Reviews, Volume 16; Number 4; Pages 2100514; 2022
DOI: 10.1002/lpor.202100514

A full-color compact 3D see-through near-eye display system based on complex amplitude modulation

Author(s):

Zhang, Zhiqi; Liu, Juan; Gao, Qiankun; Duan, Xinhui & Shi, Xueliang

Abstract:

“For complex amplitude modulation (CAM)-based three-dimensional (3D) near-eye systems, it is a challenge to realize colorful 3D display by using spatial light modulator (SLM) and grating. Here, a full-color compact 3D see-through near-eye display (NED) system by CAM is proposed. Computer generated holograms (CGHs) for different wavelengths are calculated separately. Each CGH contains two position-shifted sub-holograms and the separated distance is carefully calibrated to eliminate chromatic aberration. Colorful 3D images are synthesized through time-multiplexing. Color managements are performed and chromatic aberration of the system is analyzed to provide better colorful effect. The system structure is integrated to be compact and a prototype is implemented. Pre-compensation is added on CGHs to offset the system’s assembling errors. Optical experiment results show that the proposed system can provide good 3D full-color see-through performance without vergence-accommodation conflict (VAC). Dynamic colorful display ability is also tested, which shows good potential for interactive NED in the future.”

Link to Publications Page

Publication: Optics Express
Issue/Year: Optics Express, Volume 27; Number 5; Pages 7023; 2019
DOI: 10.1364/oe.27.007023