Title :
Fabrication of hollow waveguides with sacrificial aluminum cores
Author :
Barber, J.P. ; Conkey, D.B. ; Lee, J.R. ; Hubbard, N.B. ; Howell, L.L. ; Dongliang Yin ; Schmidt, H. ; Hawkins, A.R.
Author_Institution :
Electr. & Comput. Eng. Dept., Brigham Young Univ., Provo, UT, USA
Abstract :
We have developed a process to fabricate dielectric waveguide structures with long hollow cores formed by etching a sacrificial core material. The process is compatible with other planar silicon fabrication techniques. Using aluminum as the sacrificial material, we have investigated fabrication limits and design parameters that determine mechanical integrity of the waveguides. Internal pressure due to the production of gaseous compounds during the core removal process was identified as the yield-limiting factor. A mechanical model based on finite element analysis and confirmed by experiment, predicts ultimate pressures sustainable by these structures. Waveguides less than 10 μm wide with 2-μm-thick coatings should sustain 50 MPa of internal pressure. Low-loss guided-mode propagation in optical waveguides based on these hollow cores is demonstrated.
Keywords :
aluminium; dielectric materials; etching; finite element analysis; optical design techniques; optical fabrication; optical films; optical losses; optical waveguides; yield strength; 2 mum; 50 MPa; Al; coated waveguides; core removal process; dielectric waveguide structures; etching; finite element analysis; gaseous compounds; guided-mode propagation; hollow cores; hollow waveguide fabrication; internal pressure; low-loss propagation; mechanical model; optical waveguides; planar silicon fabrication techniques; sacrificial aluminum cores; yield-limiting factor; Aluminum; Dielectric materials; Etching; Finite element methods; Hollow waveguides; Optical device fabrication; Optical waveguides; Predictive models; Production; Silicon; Fabrication; micromachining; photonic crystals; waveguides;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2004.839446
