Ultrashort pulses with ultrahigh tunable repetition rates up to 50 GHz are produced by the use of a solid-state saturable absorber film of polymethine dyes in a polymer matrix to mode lock a neodymium glass laser. The energy and the pulse duration of the ultrashort pulses and the stability of the train are measured. The shortest duration pulses produced are ~4 ps with no noticeable change in the optical properties of solid-state dye films after several hundred shots of operation.