A simple coupled-bloch-mode approach to study active photonic crystal waveguides and lasers

Marco Saldutti*, Paolo Bardella, Jesper Mørk, Mariangela Gioannini

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

238 Downloads (Pure)


By applying a coupled-Bloch-mode approach, we have derived a simple expression for the transmission properties of photonic crystal (PhC) line-defect waveguides with a complex refractive index perturbation. We have provided physical insights on the coupling mechanism by analyzing the frequency dependence and relative strength of the coupling coefficients. We have shown the impact of the perturbation on the waveguide dispersion relation and how the gain-induced distributed feedback limits the maximum attainable slow-light enhancement of the gain itself. We have then applied our approach to analyze the threshold behavior of various PhC laser cavities and proved the significant impact of coherent distributed feedback effects in these lasers. Importantly, our approach also reveals that a structure simply consisting of an active region with zero back reflections from the passive output waveguides can achieve lasing oscillation with reasonable threshold gain.

Original languageEnglish
Article number8735893
JournalIEEE Journal of Selected Topics in Quantum Electronics
Issue number6
Number of pages12
Publication statusPublished - 1 Nov 2019


  • Bloch modes
  • Coupled-mode theory
  • Photonic crystal (phc)
  • Photonic crystal waveguides and lasers
  • Photonic integrated circuits


Dive into the research topics of 'A simple coupled-bloch-mode approach to study active photonic crystal waveguides and lasers'. Together they form a unique fingerprint.

Cite this