We report on an octave-spanning Ti:sapphire laser oscillator stabilized to carrier-envelope-offset frequency zero, generating a pulse train with constant field profile for every pulse. Stabilization is realized using an extended self-referenced locking scheme enabling to lock the carrier envelope-offset phase with less than 65 attosecond rms timing jitter. The stabilized system features a pulse repetition rate of 100 MHz with pulses as short as 4.5 fs and 220 mW average output power. With this laser system it was possible for the first time to demonstrate a spectral interference pattern of 1011 oscillator pulses in an out-of-loop f-to-2f-interferometer.