Erbium-doped aqueous polymer solutions were prepared using polyvinylpyrrolidone as a host polymer, potassium persulfate as a thermal cross-linking agent, erbium (III) trifluoromethane sulfonate as an erbium source, ethylene glycol as an antifoaming agent and DISPERBYK-180 as a dispersing agent with various weight ratios. The cross-linked, patterned and Er3+-doped polymer films were fabricated using the solutions by a lift-off process for application to planar optical amplifiers. The polymer films fabricated in this study showed excellent transmission of more than 90% over the visible and NIR regions, a high thermal decomposition temperature of about 380 degrees C and high Er3+ concentration up to 20 wt.% based on a polymer matrix without aggregation, making this material sufficient for planar optical amplifiers.