© 2019 Elsevier Ltd Electroabsorption and Mach-Zehnder modulators are routinely used to generate optical pulses for use in optical transmission systems. Both types of modulator impose dynamic frequency chirp on the generated pulses, which can lead to significant pulse broadening when transmitted in optical fiber. This paper describes the use of a modified linear pulse characterization method to measure dynamic pulse power, phase and chirp. Modulator chirp factors are determined by the use of simple models in conjunction with experimental pulse temporal profiles for 40 and 17.7 ps pulsewidth pulses at 10 and 20 GHz repetition rates, generated by the Electroabsorption and Mach-Zehnder modulators respectively.