Electrical crosstalk cancellation in acoustooptical modulators

A method for calibrating a multichannel acousto-optical modulator, comprising the steps of:

• operating one channel of a multichannel acousto-optical modulator with a modulated radio-frequency signal;
• operating another channel of said multichannel acousto-optical modulator with said modulated radio-frequency signal scaled by a factor and phase-shifted by a phase difference;
• measuring an intensity passing through said another channel of said multichannel acousto-optical modulator;
• and
• determining a factor and a phase difference giving a lowest intensity as a calibration factor and a calibration phase difference to be used for crosstalk cancellation between said two tested channels of said multichannel acousto-optical modulator.

A control unit for a multichannel acousto-optical modulator, comprising:

• an input for obtaining print data for a multitude of channels of said multichannel acousto-optical modulator;
• a modulator arrangement having a multichannel modulator control for modulating radio-frequency signals for each of said multitude of channels based on said obtained print data;
• and
• a multichannel output for providing said modulated radio-frequency signals to respective transducers of said multichannel acousto-optical modulator via electrical input connectors;
• wherein said modulator arrangement is configured for, for at least one channel, providing crosstalk cancellation giving a modulated radio-frequency signal that is compensated by a modulated radio-frequency signal of at least an electrically adjacent channel among said electrical input connectors, scaled by a predetermined factor and phase shifted by a predetermined phase difference.