The effect of wall tilt on the performance of directional couplers has been studied. There is a significant reduction in the coupling length as the tilt decreases when nonvertical walls, which are inherent in nearly all clean-room waveguide fabrication processes, are considered. Comparison of 90° and 45° coupling lengths reveals a difference of nearly a factor of 2 between them. Experimental data obtained with antiresonant reflecting optical waveguide directional couplers confirm that tilt effects should be considered in any device with large core thickness.
© 2002 Optical Society of America
[Optical Society of America ]
A. Llobera, I. Salinas, I. Garcés, A. Merlos, and C. Domínguez, "Effect of wall tilt on the optical properties of integrated directional couplers," Opt. Lett. 27, 601-603 (2002)