A new type of hybrid LC composite based on porous silicon matrix filled with nematic photochromic azobenzene containing mixture was elaborated. The composite has a photonic band gap and is itself a photonic crystal. The irradiation of the sample by UV light causes the E–Z isomerization of photochromic azobenzene component that breaks the nematic order of the LC mixture in the porous matrix and induces the photonic band gap shift (≈10 nm).
This process is completely reversible under visible light action and can be repeated many times. Observed optically induced spectral shift demonstrates the possibility to produce tunable optical filters and bistable laser resonators, switchable light blocker that can be used in energy-efficient displays and other optical elements and photonic devices.
