Due to different boundary continuity conditions, electromagnetic waves with transverse-magnetic and transverse-electric polarizations respond differently when they encounter dielectric interfaces. Based on this mechanism, we propose a self-collimating polarization beam splitter (PBS) constructed on a polarization-insensitive self-collimation photonic crystal. The splitting is realized on a Mach–Zehnder interferometer (MZI), through which the two polarizations can be separated by 90° with low cross talk. Both polarizations are self-collimated to eliminate the diffraction loss during the propagation. Furthermore, the out-of-plane scattering loss is suppressed since the PBS is operated in the first band. The wavelength bandwidth of the MZI-based PBS reaches about 100 nm at 1550 nm. Finally, the influences of interfaces on the performance of the PBS are discussed.
© 2010 Optical Society of America
Original Manuscript: December 17, 2009
Revised Manuscript: May 10, 2010
Manuscript Accepted: May 10, 2010
Published: June 11, 2010
Yi Xu, Shun Wang, Sheng Lan, Xu-Sheng Lin, Qi Guo, and Li-Jun Wu, "Self-collimating polarization beam splitter based on photonic crystal Mach–Zehnder interferometer," J. Opt. Soc. Am. B 27, 1359-1363 (2010)