Stress Effect on Polarization of Surface Emitting Lasers,
Abstract
For polarization-sensitive applications such as magneto-optic disks and coherent detection systems, the polarization state of surface emitting (SE) lasers must be well defined. From the measured polarization characteristics, it was found that the output of mesa-structure SE lasers were linearly polarized and homogeneous lasers were unstable in terms of polarization state. Several polarization control methods were also suggested. However, the stress would affect the polarization state of SE lasers and it is necessary to clarify its effect for stable polarization control. We have investigated the lasing mode of SE lasers with the elliptical etched well. This elliptical hole may produce an anisotropic stress in the active region induced by the asymmetric shape of the well. A model of SE laser with the anisotropic holed region is shown. The epitaxial layers are bent due to the difference of the thermal expansion coefficient between GaAs and AlGaAs. This provides the tensile stress difference between the major axis and the minor axis of the holed region. There are two cases, Type I and Type II which provide the differential gain along the major axis and the minor axis, respectively.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1992
- Accession Number
- ADP008100
Entities
People
- F. Koyama
- K. Iga
- T. Mukaihara
Organizations
- Tokyo Institute of Technology