Enhanced longitudinal mode spacing in blue-violet InGaN semiconductor laser

TL;DR

This paper proposes that e-h plasma oscillations cause enhanced mode spacing in InGaN lasers, with plasma resonances driven by mode beating leading to mode clustering and larger mode separation.

Contribution

It introduces a novel explanation linking plasma oscillations to mode clustering, explaining the observed enhanced mode spacing in InGaN lasers.

Findings

Plasma oscillations are responsible for mode clustering.

Resonant excitation occurs due to mode beating.

Mode separation is significantly larger than individual mode spacing.

Abstract

A novel explanation of observed enhanced longitudinal mode spacing in InGaN semiconductor lasers has been proposed. It has been demonstrated that e-h plasma oscillations, which can exist in the laser active layer at certain driving conditions, are responsible for mode clustering effect. The resonant excitation of the plasma oscillations occurs due to longitudinal mode beating. The separation of mode clusters is typically by an order of magnitude larger that the individual mode spacing.