A high-repetition-rate, femtosecond optical parametric oscillator based on bulk periodically poled lithium niobate is described. This optical parametric oscillator is continuously tunable from 1.12 to 1.50 &mgr;m in the signal branch, and signal pulses as short as 60 fs have been observed. The corresponding turning range for the idler branch is from 1.68 to 2.72 &mgr;m. Modifications which should result in a femtosecond optical parametric oscillator with a pumping threshold of less than 50 mW are discussed. ©1997 American Institute of Physics.