Soft Matter Macro and Micro-Photonics workshop

Light-programmable 3D microphotonics with liquid crystalline polymers

Sara Nocentini

National Institute of Metrological Research, Turin, Italy

European Laboratory for Nonlinear spectroscopy, Florence, Italy

Progress in integrated photonics requires the development of novel materials and advanced nano- and micro-structuring techniques to realize programmable components with low power consumption and a reduced footprint. Liquid crystalline polymers (LCPs) provide reversible variations of both shape and refractive index under light and temperature stimuli resulting in 4D microstructuring—where three-dimensional designs exhibit controlled temporal deformation— and therefore in dynamically tunable photonic structures. 

Three-dimensional nanofabrication can be achieved using custom photoresists through the  lithographic technique of two-photon direct laser writing (2P-DLW), which enables the fabrication of polymeric architectures with nanometric resolution. By optimizing the lithographic parameters of soft and elastic materials, we have demonstrated lightprogrammable integrated photonic circuits [1] and fully three-dimensional deformable photonic crystals with sub-diffraction-limited resolution and reversibly tunable stop bands [2].

While these structures operate in the linear regime, we are investigating nonlinear optical responses at low light intensities. In particular, we explore phase-encoded structural nonlinearities in polymer-dispersed and polymer-stabilized liquid crystals [3], as well as third-order nonlinear processes arising from reorientational effects in polymer-stabilized liquid crystals [4]. The nanoscale patterning of liquid crystalline polymers for integrated photonics and neuromorphic architectures, in both linear and nonlinear regimes, opens promising routes toward all-optical processing at low laser power, thereby supporting scalable advanced photonic systems.

[1] S Nocentini, F Riboli, M Burresi, D Martella, C Parmeggiani, DS Wiersma, 2018. ACS Photonics 5 (8), 3222.

[2] De Bellis, I., Martella, D., Parmeggiani, C., Wiersma, D.S. and Nocentini, S., 2023. Adv Funct Mater, 2213162.

[3] Nocentini, S., Rührmair, U., Barni, M., Wiersma, D. S., & Riboli, F., 2024. Nat Mater, 23(3), 369.

[4] Massarelli, F., Wiersma, D. S., Riboli, F., & Nocentini, S., 2025. Liquid Crystals, 1-10.

Part of this research project was financed by the European Union, Horizon ERC Stg 3DnanoGiant (n° 101163799)