Abstract: The present disclosure relates to devices, systems and techniques for producing asynchronous delta-sigma modulated output signals from an optical input signal. In some examples, a modulator may include a first inverted integrator for producing a first integrated optical signal based on the optical input signal. Example modulators may also include a second inverted integrator for producing a second integrated optical signal based on the first integrated optical signal. Example modulators may also include an optical quantizer for producing an optical output signal based, at least in part, on the second integrated optical signal.