Amplification characteristics of graded-index (GI) type organic dye doped polymer optical fiber amplifiers (POFAs) are discussed. As an organic dye for optical amplification, Rhodamine 6G, Rhodamine B, and Perylene Red are doped in the core region of polymer optical fibers (POFs). These POFA can obtain optical gain in the visible region of wavelength from 570 nm to 620 nm. POFA is promising for extraordinary high power optical amplification in comparison with rare-earth ions doped silica fiber amplifier. For example, output power of 1 kW with a gain of 30 dB can be obtained by using a Rhodamine B doped POFA at a low dye concentration of 1 ppm. Additionally, a novel solid-state POFA amplifier system is demonstrated.