A tolerant single etch-step passive polarization splitter on InP/InGaAsP is designed and fabricated. The device consists of a directional coupler with a wide and a narrow waveguide. Modal birefringence of the third-order modes for transverse electric (TE) and transverse magnetic (TM) polarizations is employed to selectively couple one polarization. Tapering is applied to increase the tolerances. The devices are characterized, and the measurement results show good agreement with the beam-propagation-method simulations: a splitting ratio larger than 95% for a width range of around 100 nm and over a large wavelength range, covering at least the C-band.
© 2007 IEEE
Luc M. Augustin, Jos J. G. M. van der Tol, Rabah Hanfoug, Wim J. M. de Laat, Michael J. E. van de Moosdijk, Paul W. L. van Dijk, Yok-Siang Oei, and Meint K. Smit, "A Single Etch-Step Fabrication-Tolerant Polarization Splitter," J. Lightwave Technol. 25, 740-746 (2007)