Modeling of self-sustained pulsation based on two-section distributed feedback lasers with shift-layer
Journal
Japanese Journal of Applied Physics
Journal Volume
49
Journal Issue
12
Date Issued
2010
Author(s)
Abstract
We propose a numerical model to estimate the self-sustained pulsation frequency (SSP frequency) for a two-section distributed feedback laser (TS-DFB). A modulation transfer function is derived from the rate equations for carriers and photons. The SSP frequency can be obtained from the singularity condition of the transfer function. A useful but simple systematic design procedure is proposed for investigating the effects of various structural parameters on the SSP condition. The device parameters varied in the analysis include carrier density, section length ratio, grating coupling coefficient, and the refractive index change caused by adding a shift-layer. The device structure used for the SSP experiments and analysis is a TS-DFB laser with a shift-layer. This type of lasers can have stable lasing mode with large side-mode suppression ratio such that the inherent mode instability in a conventional index-guide DFB laser can be eliminated in this structure. This can simplify the operation of the SSP laser. The analysis model can also be applied to other laser structures. The results of numerical analysis match well with the experimental data.
Type
journal article