Low finesse Fabry-Perot cavities for wide spaced frequency combs with large spectral bandwidth

We use low finesse Fabry-Perot cavities in series to generate frequency combs with large mode spacing by simultaneously maintaining high spectral bandwidth. The attenuation of laser modes closest to the pass band exceeds 70 dB relative to the modes centered within the pass band for a 5 GHz Fabry-Perot filtering a 250 MHz frequency comb.