Anisotropic radiation pattern from InGaAlP quantum well mesa-like microdisks

To overcome the isotropic directional emission of an ideal circular microdi sk, two kinds of cylindrical mesa-like InGaAlP single quantum well (SQW) mi crodisks emitting at a visible red wavelength of 0.66 mu m have been fabric ated. An anisotropic luminescence pattern was revealed by the microscopic f luorescence (FL) image. FL intensity, preferentially enhanced with twofold symmetry, appeared at the circumference of the InGaAlP SQW microdisks. Our results demonstrated that anisotropic radiation can be achieved by geometry shaping of the disks on the top view two-dimensional boundary slightly def ormed from circular shape and/or on the side-view cross-section of the circ ular mesa by wet etching anisotropic undercut. (C) 2000 Elsevier Science Lt d. All rights reserved.