Optical study of GaAs/AlAs pillar microcavities with elliptical cross section

GaAs/AlAs pillar microcavities with elliptical cross section have been fabricated by molecular beam epitaxy, electron-beam lithography, and reactive ion etching. We study their lowest energy confined photonic modes by photoluminescence, using a quantum box array placed inside the cavity as an internal broadband light source. Such an anisotropic cross section allows to split the twofold polarization degenerate fundamental mode of circular micropillars into a pair of orthogonal linearly polarized modes. Their energy splitting, which is well accounted for by a simple perturbative model, is studied experimentally and theoretically as a function of the eccentricity and average radius of the pillars. Splittings as large as 15 meV are observed, which is very encouraging for applications ranging from the improvement of the polarization locking in vertical cavity lasers to the fabrication of light emitting diodes with a better control of the spontaneous emission.

[1]  Kenichi Iga,et al.  Surface emitting semiconductor lasers , 1988 .

[2]  J. P. Harbison,et al.  Low threshold electrically pumped vertical cavity surface emitting microlasers , 1989, Annual Meeting Optical Society of America.

[3]  Axel Scherer,et al.  Transverse modes, waveguide dispersion, and 30 ps recovery in submicron GaAs/AlAs microresonators , 1989 .

[4]  Charles Vassallo,et al.  Optical Waveguide Concepts , 1991 .

[5]  Kenichi Iga,et al.  Intensity noise and polarization stability of GaAlAs-GaAs surface emitting lasers , 1991 .

[6]  J. P. Harbison,et al.  Polarisation characteristics of quantum well vertical cavity surface emitting lasers , 1991 .

[7]  J. Oudar,et al.  Reduced threshold all‐optical bistability in etched quantum well microresonators , 1994 .

[8]  K. Choquette,et al.  Control of vertical-cavity laser polarization with anisotropic transverse cavity geometries , 1994, IEEE Photonics Technology Letters.

[9]  Henryk Temkin,et al.  Polarization instability and relative intensity noise in vertical‐cavity surface‐emitting lasers , 1995 .

[10]  Henri Benisty,et al.  Confined Electrons and Photons , 1995 .

[11]  L. Coldren,et al.  Calibrated intensity noise measurements in microcavity laser diodes , 1995 .

[12]  E. Costard,et al.  Quantum boxes as active probes for photonic microstructures: The pillar microcavity case , 1996 .

[13]  Thomas D Milster,et al.  Polarization switching control in vertical-cavity surface-emitting lasers , 1997 .