Figure 9
From: High Speed All Optical Nyquist Signal Generation and Full-band Coherent Detection

The power differences and the phase relation of the generated 5-tone comb by varying the normalized driving voltage and the DC bias.
(a) shows the power difference of the 5 tone-comb versus the normalized driving voltage and the DC bias; (b) shows the phase relation of 5 tones versus the driving voltage and DC bias.