A polymer-based multimode interference optical splitter chip has been designed and fabricated. Fiber-waveguide coupling loss as well as the structure of the multimode waveguide are optimized in the design to achieve higher performance. A simple UV-based soft nanoimprint lithography (Soft UV-NIL) technique is adopted in the fabrication. Fluorinated acrylate resins, LFR, with different refractive indices are used in this work. Both the residual layer and waveguide deformation are improved by controlling the fabrication processes. An average of 12.98 dB insertion loss is obtained from 1×4 splitters with 1.08 dB uniformity and 0.05 dB polarization-dependent loss. The validity of the polymer optical splitters fabricated through Soft UV-NIL technique is demonstrated by software simulation as well as experimental works.
Proc. SPIE. 9685, 8th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Design, Manufacturing, and Testing of Micro- and Nano-Optical Devices and Systems; and Smart Structures and Materials
A polymer-based multimode interference (MMI) optical splitter chip has been fabricated through UV-based soft imprint lithography (Soft UV-NIL) technique. Propagation loss and bending loss are considered during the chip design in order to decrease the insertion loss. UV curable fluorinated acrylate resin is used due to its low material absorbing loss. 1×4 cascaded MMI splitter is fabricated and measured at 1550 nm optical wavelength and an average 12.38 dB insertion loss is obtained together with an 1.23 dB uniformity.