Integration and Evaluation of Multichannel Photonic Crystal Wavelength Filters Consisting of Autocloned Ta₂O₅/SiO₂Multilayer Thin Films

Abstract

Angular distributions have been measured for deuteron elastic scattering from 46Ti and for the 46Ti (d, p) 47Ti reaction at energies of Ed = 7 and 10 MeV. Many of the angular distributions, in particular those from weakly excited states, cannot be reproduced by DWBA calculations. When compound-nucleus cross sections calculated using a Hauser-Feshbach model are added incoherently to those from the DWBA calculations it is found that satisfactory fits can be obtained to almost all angular distributions showing forward peaking. For several levels including the ground state of 47Ti there is no evidence of any forward peaking and it is found that these levels can be reproduced by the Hauser-Feshbach calculations alone. It is found that for the level at E, = 1.245 MeV the angular momentum transfer ( I = 1) deduced from the angular distribution is not consistent with the adopted J" value of Bfor this level.

Design and Fabrication of Multichannel Photonic Crystal Wavelength Filters to Suppress Crosstalk of Arrayed Waveguide Grating

“…Our group has reported a Si/SiO 2 material system for PC filters and its fundamental band-pass function, in which the transmission wavelength of the PC filters shifted by about þ30 nm as the in-plane lattice constant of the PC filters increased from 300 nm to 500 nm. 10) Although Si/SiO 2 is an attractive combination at near-infrared wavelengths by virtue of its large refractive index contrast, we changed the material system from Si/SiO 2 to Ta 2 O 5 /SiO 2 . 10) This is because Ta 2 O 5 is believed to be more stable than Si over the long-term use when applied to actual WDM systems.…”

“…First, we designed the photonic bandgap (PBG) wavelength ranges of the DBRs of the PCs by calculating the photonic dispersion relation of an infinite PC by using the 3D finite-difference time-domain (FDTD) method. 10,11) Figure 2(a) shows the unit cell of a typical autocloned 3D PC with various in-plane lattice constants (L x ). In this study, we fabricated patterned substrates with L x equal to L y in order to make the transmission spectra of the PC filters independent of polarization sensitivity.…”

“…We fabricated Ta 2 O 5 /SiO 2 PC filters with a Ta 2 O 5 cavity according to the design described in §3.1. 10) We first formed arrays of holes in a square-lattice configuration on a fused silica substrate by electron-beam lithography and dry etching. The lattice constants were 400, 600, and 800 nm.…”

Fabrication of three-dimensional autocloned photonic crystal on sapphire substrate

“…The deposition parameters of the films have to be properly controlled [3,4] such that the periodically corrugated substrate profile can be automatically replicated through the films. Depending on the application of the APhC, the substrate could be silicon for a photonic crystal waveguide [5,6], glass for a polarization selective grating [7], and wavelength filters [8]. It is important to note that the starting profile of the corrugated substrate has to be well patterned periodically.…”

The Dry Etching of TiN Thin Films Using Inductively Coupled CF4/Ar Plasma

“…The photoelectron binding energy of 685.2 eV was assigned to F 1s, resulting from the less volatile TiF x , leading to an increased etch rate with increasing amount of CF4 . When the TiN thin films were etched in the CF 4 /Ar (20:80%) and pure CF 4 plasmas, the F 1s peak intensity decreased, owing to the F atoms from CF 4 gas[15][16][17].…”