Tunable defect states in 1D photonic bandgap nanostructures

The fabrication of one dimensional photonic bandgap nanostructures is described and the optical properties of these structures are examined. Using a deposition technique known as a glancing angle deposition (GLAD), porous films with a predefined nanoscale geometry are created. Specifically, in the present work we consider GLAD fabricated thin films characterized by periodically varying refractive index in one-dimension. We introduce a variety of planar defect layers into the structures and investigate the resulting changes observed in the photonic bandgap of the system. Theoretical simulation of transmittance spectra of GLAD fabricated films is performed with the finite-difference time-domain (FDTD) method and the results are compared with experimental measurements. Modifications of the transmittance spectra are investigated by changing the geometry of the defect layer and varying the void region effective index. It is shown that the spectral width and location of states within the bandgap is controlled by the geometry of defect and film microstructure. Active tunability of the defect states is obtained by considering infilling of the void regions of the structure with nematic liquid crystals and then analyzing the optical spectrum for various orientations of the liquid crystal director axis.

[1]  James N. McMullin,et al.  Inhomogeneous thin film optical filters fabricated using glancing angle deposition , 1997 .

[2]  Zhang,et al.  Electromagnetic wave propagation in periodic structures: Bloch wave solution of Maxwell's equations. , 1990, Physical review letters.

[3]  T Motohiro,et al.  Thin film retardation plate by oblique deposition. , 1989, Applied optics.

[4]  Jeremy C. Sit,et al.  Characterization By Variable Angle Spectroscopic Ellipsometry Of Dielectric Columnar Thin Films Produced By Glancing Angle Deposition , 2003 .

[5]  B. Bovard,et al.  Derivation of a matrix describing a rugate dielectric thin film. , 1988, Applied optics.

[6]  William H. Southwell,et al.  Spectral response calculations of rugate filters using coupled-wave theory , 1988 .

[7]  H. Angus Macleod,et al.  Structure‐related optical properties of thin films , 1986 .

[8]  H. Haus,et al.  Antisymmetric taper of distributed feedback lasers , 1976, IEEE Journal of Quantum Electronics.

[9]  E. Yablonovitch,et al.  Inhibited spontaneous emission in solid-state physics and electronics. , 1987, Physical review letters.

[10]  Kevin Robbie,et al.  Advanced techniques for glancing angle deposition , 1998 .

[11]  Kate Kaminska,et al.  Vacuum evaporated porous silicon photonic interference filters. , 2003, Applied optics.

[12]  M. Brett,et al.  Gradient-index narrow-bandpass filter fabricated with glancing-angle deposition. , 2004, Optics letters.

[13]  Leon Abelmann,et al.  Oblique evaporation and surface diffusion , 1997 .

[14]  John,et al.  Strong localization of photons in certain disordered dielectric superlattices. , 1987, Physical review letters.

[15]  Dirk J. Broer,et al.  Optical activity of chiral thin film and liquid crystal hybrids , 2001 .

[16]  Katsumi Yoshino,et al.  Disappearances of uncoupled modes in two-dimensional photonic crystals due to anisotropies of liquid crystals. , 2003, Physical review. E, Statistical, nonlinear, and soft matter physics.

[17]  M. J. Brett,et al.  Sculptured thin films and glancing angle deposition: Growth mechanics and applications , 1997 .