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.

Deoxyribonucleic acid (DNA) biopolymer was used as optical waveguide core material, and reactive ion-beam etching process was used to form channel waveguides. The etching conditions were optimized and the waveguides were characterized optically.