Er 3+ -doped Y 2 Ti 2 O 7 and Er 2 Ti 2 O 7 thin films were fabricated by sol–gel spin-coating method. A well-defined pyrochlore phase Er x Y 2- x Ti 2 O 7 was observed while the annealing temperature exceeded 800°C. The average transmittance of the Er x Y 2- x Ti 2 O 7 thin films annealed at 400 to 900°C reduces from ∼87 to ∼77%. The refractive indices and optical band gaps of Er x Y 2- x Ti 2 O 7 (x=0–2) annealed at 800°C/1h vary from 2.20 to 2.09 and 4.11 to 4.07eV, respectively. The ∼1.53μm photoluminescence spectrum of Er 3+ (5mol%)-doped Y 2 Ti 2 O 7 thin films annealed at 700°C/1h exhibits the maximum intensity and full-width at half maximum (∼60nm).