Characterization of the modulation and noise properties of a three-electrode DFB laser

The modulation and noise properties of a three-electrode DFB laser have been measured. At proper biasing, the frequency modulation response could be chosen to be in phase or 180 degrees out of phase with respect to the intensity modulation by selecting the modulated electrode. Applying a first order equalization/filter, a flat frequency modulation response was measured up to 5 GHz. A 20-dB broadband suppression of the intensity modulation was accomplished when modulating two sections in push-pull. The spectral densities of the FM and intermodulation noise were measured showing remarkably flat intermodulation and FM noise spectra.<
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