We synthesize heterofluorene monomers with Si, Ge, N, As, Se, and Te occupying the 9-position of the fluorene motif, which are then polymerized by Suzuki coupling. The optical properties of the obtained polymers are investigated in their solid state. We compare and elucidate effects in the materials absorption, emission, quantum yield (Phi), and fluorescence lifetime. Moreover, we determine the refractive indices n and absorption coefficient k by variable angle spectroscopic ellipsometry (VASE). We show that in addition to already known C, Si, and N containing polyfluorenes also Ge and As containing polymers exhibit amplified spontaneous emission.