Compact polarization-insensitive biopolymer multimode interference waveguide splitter

Compact 1×4 multimode interference splitter with tapered sections has been designed and fabricated based on deoxyribonucleic acid- cetyltrimethylammonium biopolymer material. A multistep processing and reactive ion etching technique have been developed to fabricate the device. There is excellent agreement between experimental and theoretical results and the splitter exhibits low excess loss, negligible polarization dependent loss, and well output uniformity for both TE and TM modes at 1550 nm wavelength. © 2009 American Institute of Physics.