Patent ID: 7440703
Filing Date: 2008-10-21
Classification: G02F,H04B

Abstract:
1. An arrangement for generating a high speed optical output signal modulated by an input data pattern, the arrangement comprising an electro-optic modulator responsive to an optical input signal and a modulating electrical input signal for generating the modulated optical output signal, the electro-optic modulator comprising a free carrier-based modulator utilizing changes in carrier density to generate the modulated optical output signal; an equalizer/pre-emphasis module disposed at the electrical input to the electro-optic modulator, the equalizer/pre-emphasis module for inserting a first pre-emphasis pulse of a predetermined magnitude and a predetermined duration into the modulating electrical input signal at each transition between a first data value and a second data value of the input data pattern and inserting a second pre-emphasis pulse of a predetermined magnitude and a predetermined duration at each transition between the second data value and the first data value, the second pre-emphasis pulse having a polarity opposite to the first pre-emphasis pulse, the inserted first and second pre-emphasis pulses for extending the bandwidth of the electro-optic modulator without increasing the optical loss thereof; and a control module responsive to a portion of the modulated optical output signal for measuring the modulated optical output signal and determining optimum values for at least one operating parameter from the set of: the first pre-emphasis pulse duration, the second pre-emphasis pulse duration, the first pre-emphasis pulse magnitude and the second pre-emphasis pulse magnitude, the control module including a feedback element to continuously measure a portion of the modulated optical output signal and update the magnitude and duration values of the first and second pre-emphasis pulses in association with changing operating conditions, the control module further comprising a look-up table including listings of pre-emphasis pulse magnitude and duration values associated with changing operating conditions.