Multi-electrode complex-coupled DFB lasers for reduced spatial hole burning

The effects of using multiple electrodes to reduce longitudinal spatial hole burning (LSHB) in a complex-coupled distributed feedback (DFB) laser are investigated. Using a time-domain model, we show that LSHB can be compensated by injecting more current into the center of the device. We also find that differential current injection has an effect on the threshold current and quantum efficiency of the DFB laser. Spectral characteristics are obtained by fast Fourier transform (FFT) of the time-domain data and we show that inhomogeneous current injection can also have an effect on the laser linewidth.