Abstract

Silica-on-silicon (SiO₂/Si) waveguide devices show great promise for practical integrated optical circuits. One of the challenges of this technology is to overcome the intrinsic strain birefringence which causes polarization dependent response. A number of methods have been suggested and demonstrated to achieve polarization independent response^[1-4]. We present a novel method for achieving polarization independence in SiO₂/Si waveguide devices by placing a thin patch of silicon nitride (Si₃N₄) under the waveguide core to achieve polarization independence in Mach-Zehnder interferometers (MZIs) and for compensation of polarization dependent loss (PDL). Our method requires an additional photolithography step but does not but does not require active tuning and is applicable to a wide variety of SiC₂/Si waveguide devices.

© 1993 Optical Society of America