We studied both experimentally and numerically the spectral behavior of modal birefringence in channel waveguides inscribed in PMMA by DUV illumination. The measurements of birefringence were carried out using spectral interference method for different waveguide widths, respectively 2, 3, 4, 5, 6 μm which were inscribed using 3 J/cm². We have also modeled the spectral dependence of birefringence related only to waveguide geometry using FEM method. High discrepancy reaching one order of magnitude was observed between measured and calculated birefringence. This is related to the fact that numerical analysis accounts only for so called geometrical birefringence induced by the asymmetry of the waveguide, while in measurements the overall modal birefringence relates to both the geometrical and the material effect. Our measurement results indicate that the contribution of the material birefringence in the analyzed waveguides may reach up to 3×10^-4 in a short wavelength range.

Date Published: 16 May 2007
PDF: 5 pages
Proc. SPIE 6585, Optical Sensing Technology and Applications, 65851W (16 May 2007); doi: 10.1117/12.722959

Published in SPIE Proceedings Vol. 6585:
Optical Sensing Technology and Applications
Francesco Baldini; Jiri Homola; Robert A. Lieberman; Miroslav Miler, Editor(s)