In this work, we investigated the possibility of application of magnetophotonic crystals to the optical magnetic field
sensor. The structure of 1D-MPC was (Ta<sub>2</sub>O<sub>5</sub>/SiO<sub>2</sub>)<sup>5</sup>/Bi:YIG/ (Ta<sub>2</sub>O<sub>5</sub>/SiO<sub>2</sub>)<sup>5</sup> (magnetic material as a defect layer between
two Bragg reflectors) on a fused quarts substrate using RF magnetron sputtering apparatus. We used Bismuth substituted
yttrium iron garnet (Bi:YIG) polycrystal film as a defect layer, because Bi:YIG is well known as the magnetic material
with effective MO properties, even if it is polycrystal. Due to specially designed structure, the localized mode appeared
at the wavelength of 880 nm, which is tunable by the thickness of multi layers or defect layer. At the wavelength of
localized mode, Faraday rotation was shown large enhancement of 1.5°, that is fifty times larger than for single Bi:YIG
polycrystal film of the same thickness.
Optical properties of mesoporous three-dimensional photonic crystals (3D PCs) based on thin opal films were found to be extremely sensitive to a humidity of the surrounding air. It was manifested that the internal structure of a single SiO<sub>2</sub> sphere together with the net of voids between them in a thin opal film acts as a sponge for wet steams. Our experimental data have shown that hydrophilic internal structure of a mesoporous film sponges up (and lose) water (dry or wet steams) that influences dielectric permittivity, the latter causes significant changes in transmission spectra. High sensitivity, quick response and possibility of contactless measurements makes sensors based on optical effects in mesoporous PCs to be very promising. It concerns not only humidity sensors, but also sensors of various gases, temperature, deformation and other environmental impacts.
Highly transparent polycrystalline lanthanum-modified lead zirconate titanate (PLZT) thick films were prepared using
aerosol deposition method (ADM) of calcined complex powders. Effects of incident angle of aerosol and particle size as
well as annealing temperature on optical and electro-optic properties of films were investigated. The film with higher
transparency was obtained with smaller particle, because the aggregation frequency of particles in aerosol decreased with
reducing the particle size. The transparency of the films increased with decreasing the incident angle of aerosol. This is
presumably due to the fact that the optimal incident angle of aerosol results in the reduction of impurity and pore, which
makes the film to be denser micro-structurally. The XRD peaks of as-deposed films shifted to lower angle side,
indicating that large compressive stress, which was generated by mechanical collision of particles, acted in the films. But
the stress was eliminated through annealing process. The birefringence change in annealed film increased exponentially
with an applied electrical field to reach 0.0036 at 100kV/cm. To make a multimode waveguide, the PLZT film with 22
μm thick was formed into a silicon groove, which was fabricated through anisotropic wet etching process. The far field
profile of multimode optical wave transmitted through the fabricated PLZT waveguide was successfully observed and
could be controlled with an applied electrical field.