Photonic Crystals (PhCs) have been found to have exotic properties, such as the high dispersion and the slow group
velocity, at different frequency range. It has also been reported that the photonic crystal can behave like a negative index
material that is similar to the metallization based metamaterials composed of ring resonators and wires. It is essential to
have knowledge about the effective properties of a photonic crystal to evaluate its performance. Here, we discuss a
photonic crystal with air holes etched in a multilayer dielectric material. This structure can be cascaded to a three
dimensional photonic crystal by simply stacking the porous multilayer film. Light is propagating perpendicularly through
the multilayer film, and the transmission and reflection including both the magnitudes and the phases are obtained
through numerical simulation. Effective properties along this direction, including the permittivity, the permeability and
the effective refractive index, are calculated. From these basic and essential properties, other features such as dispersion,
group velocity can be derived.
Optical absorption, excitation and emission spectra of Nd3+ in PLZT ceramics have been studied. Based on the Judd-Ofelt (J-O) theory, the J-O intensity parameters are calculated to be Ω2=0.7199x10-20 cm2, Ω4=1.045x10-20 cm2, Ω6=0.9234x10-20 cm2 from the absorption spectrum of Nd3+-doped PLZT. The J-O intensity parameters have been used to calculate the radiative lifetime (0.385 ms) of the excited 4F3/2 level. The stimulated emission cross-sections and the fluorescence branch ratios for the 4F3/2 -> 4IJ transitions are also evaluated. We have also measured 1.068 mm fluorescence lifetime (0.168 ms) and calculated its Quantum efficiency (0.44). Under 807 nm excitation, the green and red upconversion luminescence from Nd3+ centers in the ceramic was observed at room temperature. Analysis reveals that Nd3+-doped PLZT is promising for the use as efficient optically amplifying or zero-loss electro-optical devices in telecommunication networks.
We report on the growth of erbium doped ZrF4-LaF3- BaF2 glass films by metalorganic chemical vapor deposition (MOCVD) for the construction of planar waveguide devices. Our process provides the growth of high quality, uniform in thickness, and continuous films on a wide variety of common substrates. A protective layer of MgF2 was deposited in-situ onto the Er-doped glass films under the same CVD deposition conditions. The luminescence of Er around 1.55 micrometers was observed in films on all the substrates used. The emission line shapes are the same as those observed from Er-doped fluorozirconate glass. MOCVD proved to be a feasible technology to grow rare-earth doped fluoride films for planar waveguide devices.