The optical properties and characteristics of rare earth-doped polymers have been studied to evaluate their viability for use in amplifier and laser applications. Rare earth ions are encapsulated in organic, covalent bonded chromophores. The optical properties of various rare earth chromophores doped into polymers are measured and calculated and are then used in numerical simulations of amplifiers and lasers. The result provide an estimate of their potential device performance and establish the fundamental bases for these applications in photonics. Owing to their distinct and important advantages, such as chromophore energy transfer effects, high rare earth ion concentrations, shielding of the ion from high energy vibrations of the host, enhanced optical transition moments, and controllable decay rates and branching ratios, rare earth-doped polymers are found to be promising candidates for various device applications. Numerical simulations for samarium chromophore, for example, indicate that gains about 10 dB and greater are achievable in relatively short polymer optical fiber amplifiers operating at 650nm.