An optical filter that includes a resonator cavity comprised of a saturable absorber material is provided. An input signal waveguide, a non-resonant wavelengths output waveguide, and a resonant wavelength output waveguide are coupled to the cavity. A refractive index of the saturable absorber material is altered so that a resonant wavelength output is directed down the resonant wavelength output waveguide and non-resonant wavelengths are directed down the non-resonant wavelengths output waveguide.