Ditherless optical modulator control

A method of controlling the operating parameters of an optical modulator, without using a dither signal, is provided. Past operating parameters are compared to present operating parameters using a quality of modulation signal obtained by cross-correlating the data modulation signal used to drive the optical modulator with the modulated optical signal output from the optical modulator. The quality of modulation signal is used to optimize the operating parameters (e.g., bias point) of the optical modulator, or other operating parameters of the arrangement, such as the modulator drive level, timing alignment, etc.