Application of the spectral index method to laser diode design

Abstract

Abstruct-The spectral index method (SIM) is compared to the effective index method (EIM) and the beam propagation method (BPM) for the calculation of the optical mode index and mode profile in a prototypical distributed feedback (DFB) rib waveguide laser diode. Modal index is shown to be insufficient as a metric of comparison, so in addition to Tamode, the quantum well filling factor r and grating coupling coefficient K are included in the metric for comparison. SIM is found to yield superior results to EIM and to give results comparable to BPM almost two orders of magnitude faster.