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We propose an optical sensor based on the inverse opal (IOP) photonic structure infiltrated by a typical liquid crystalline material doped by the reactive compounds. Benefiting from the unique photonic property of the IOP structure, the composite sensor shows not only a typical textural change but also a responsive photonic band gap (PBG) upon the exposure to butylamine (BA) vapour, due to the reorientation of the liquid crystalline molecules induced by the chemical reaction between the dopant and the BA vapour. This approach simplifies the measurement process by capturing the PBG signal instead of the polarised optical texture, which does not require high cost or complex instruments and might be instructive for detecting other volatiles. [ABSTRACT FROM AUTHOR]

The evolution of the characteristics of one-dimensional phase diffraction structures during their optical induction by Bessel-like monochromatic beams in photorefractive samples of lithium niobate is studied experimentally. Both, one-dimensional (1D) and two-dimensional (2D) Bessel-like beams with different topology of 2D beam cross-sections are formed from Gaussian laser beams using the amplitude masks with rectangular and annular apertures. These almost diffraction-free light fields with wavelengths of 457 and 532 nm can change the refractive indices of photorefractive lithium niobate samples and form within them the nonlinear photonic diffraction structures. [ABSTRACT FROM AUTHOR]

The planar orientation of Nematic Liquid crystal (NLC) molecules on the surface of (111) plane of silica photonic structure has been investigated. Nano voids of silica photonic crystal has been obtained by vertical deposition technique on indium tin oxide-coated substrate. NLC was infiltrated into the channels of voids in the photonic structures. Optical texture studies under with and without electric field were applied to investigate the NLC orientation. It is observed that NLC molecules in the nano voids of silica photonic structure exhibit an excellent planar alignment. This obtained hybrid composite structure on infiltration of NLC will be a promising candidate for electro optic applications. [ABSTRACT FROM PUBLISHER]