A method and apparatus for tunable filter linearization of a Fourier-Domain Mode Locking (FDML) laser for a SS-OCT comprising the steps of: choosing a fundamental frequency that avoids the mechanical resonance frequencies of a tunable filter; summing two or three harmonically related sinusoids of the fundamental frequency; and tuning the amplitudes and phases of the summed sinusoids to compensate for nonuniformities in amplitude and phase responses of the tunable filter.