Optimized design and fabrication of integrated-optic 1 x 32 and 2 x 32 "multifunnel" power splitters in polymer

We present the optimized design and the fabrication of an integrated-optic 1 x 32 multifunnel power splitter and the extension to a 2 x 32 splitter of the same type which we are the first to report.. This splitter type operates by receiving the radiated input power at the end of a slab waveguide by funnel shaped waveguides of increasing width to compensate for the power decrease towards the outer parts. Using cycles of BPM simulation and adapting the width of the receiver waveguides according to the calculated intensity distribution we archived a maximum excess loss of 0.5 dB in the simulation. The 2 x 32 splitter was designed using two input waveguides placed symmetrically 8 mu m off-center and facing the center of the receiver region. Both splitters were fabricated by UV exposure of PMMA with photo initiator BDK. The realized 1 x 32 splitter shows an excess loss 0.7 dB compared to a reference waveguide and a standard deviation of 0.5 dB with a maximum loss of 1.8 dB at lambda = 1320 nm, the 2 x 32 splitter has 1.3 dB excess loss 0.8 dB standard deviation and 2.5 dB maximum loss.