We report the first demonstration to our knowledge of passive mode locking in a diode-pumped Er(3+) and Yb(3+) codoped YAl(3)(BO(3))(4) laser operating in the 1.5-1.6 microm spectral region. Low-loss GaInNAs quantum-well semiconductor saturable absorber mirrors are used for the initiation and stabilization of the ultrashort-pulse generation. Pulses as short as 4.8 ps were generated at 1530 nm with an average output power up to 280 mW for 2 W of absorbed pump power produced by a high-brightness tapered 980 nm laser diode. Passive mode locking has also been demonstrated around 1555 nm with typical average powers of around 100 mW and pulse durations of 5.1 ps.