Tunable and free-form planar optics


The advent of spatial control over the phase and amplitude of light waves has profoundly transformed photonics, enabling major advances in fields from imaging and information technology to biomedical optics. Here we propose a method of deterministic phase-front shaping using a planar thermo-optical module and designed microheaters to locally shape the refractive index distribution. When combined with a genetic algorithm optimization, this SmartLens can produce free-form optical wavefront modifications. Individually, or in arrays, it can generate complex functions based on either pure or combined Zernike polynomials, including lenses or aberration correctors of electrically tunable magnitude. This simple and compact concept complements the existing optical shaping toolbox by offering low-chromatic-aberration, polarization-insensitive and transmission-mode components that can readily be integrated into existing optical systems.

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Fig. 1: Principle of the electrically tunable micro-optic device.
Fig. 2: Modelling and wavefront engineering procedure.
Fig. 3: Wavefront engineering.
Fig. 4: Generation of tunable annular and Bessel–Gaussian beams.
Fig. 5: Tunability ranges and response times for four different spiral sizes.
Fig. 6: Broadband multiplane imaging with a SmartLens array.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.


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The authors acknowledge financial support from the European Research Council programme under grants ERC-CoG QnanoMECA (64790) and ERC-PoC (680898), Fundació Privada Cellex, the CERCA programme and the Spanish Ministry of Economy and Competitiveness, through the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (SEV-2015-0522), Agence Nationale de la Recherche (ANR Neocastip and ANR BoroGaN) and Région Ile de France (GeneTherm Project–C’Nano IdF–DIM Nano-K 2016-16). The authors also thank J.G. Guirardo, J. Canet-Ferrer, J. Berthelot and A. Reserbat-Plantey for their help with resistor fabrication. The authors thank V. D’Ambrosio for help with data analysis and general discussions on the technology, P. Del Hougne for preliminary COMSOL simulations as well as I. Alda, R. Marty and J. Donner for their preliminary work on SmartLens characterization. The authors also thank P. Bohec for stimulating discussions regarding genetic algorithm implementation and G. Baffou for fruitful discussions on the thermal model.

Author information




R.Q. initiated and supervised the project. R.Q. and P.B. conceived the concept. P.B. developed the electro-thermo-optical model and the genetic algorithm optimization. P.B. and L.P. designed the sample. J.O. and L.P. fabricated the devices. P.B., G.T. and L.P. performed the wavefront sensing experiments and analysed the results. C.L. performed the experiment on Bessel beam generation. P.B., R.Q., L.P., A.A., M.M.M. and B.M.A. designed and performed the imaging experiment. All authors participated in writing the manuscript.

Corresponding authors

Correspondence to Pascal Berto or Romain Quidant.

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Competing interests

The authors declare the following competing financial interests: P.B., L.P. and R.Q. of the Institute of Photonic Sciences (ICFO) have filed several patent applications related to SmartLenses.

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Supplementary information

Supplementary Information

This file contains more information about the work, Supplementary Figs. 1–13 and Supplementary Tables 1–2.

Supplementary Video 1

Video showing the simultaneous refocusing of different objects located in different planes

Supplementary Video 2

Video showing simultaneous multiplane imaging in microscopy

Supplementary Video 3

Video showing the genetic algorithm optimization in the case of a conical wavefront (N = 7)

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Berto, P., Philippet, L., Osmond, J. et al. Tunable and free-form planar optics. Nat. Photonics 13, 649–656 (2019). https://doi.org/10.1038/s41566-019-0486-3

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