Abstract: A light propagation region is divided into a plurality of subregions, each subregion being limited within a minimum spatial resolution unit where an interference occurs between discrete points, and a 0-order diffraction pattern of a Fraunhofer diffraction image is detected If a convex lens and either a pinhole or an optical fiber which is disposed on a focal plane of the convex lens are employed and the diameter of the pinhole or the core diameter of the optical fiber is set to be not greater than the first dark ring of a Fraunhofer diffraction image produced by the convex lens, it is possible to take out the greater part of the energy of a plane wave component that enters the lens from a predetermined direction and remove other components from different directions, i.e., scattering component. If a plurality of optical systems of this type are bundled together, only a plane wave with a one- or two-dimensional intensity distribution can be taken out with high brightness and high resolving power.

Abstract: A surface emission type semiconductor light-emitting device includes a base having a main surface, a current blocking layer formed on the base, and a semiconductor layer formed on the current blocking layer. A circular recess or hole having a side wall which is substantially perpendicular to the main surface is formed in the semiconductor layer as extending therethrough and partly into the base. An impurity is introduced into the semiconductor layer through the side wall and thus there is defined a cylindrical diffusion region around the recess. A p-n junction is defined at an outer boundary of the diffusion region and the p-n junction effectively defines a light-emitting activation region. An additional diffusion region may be formed in the semiconductor layer for narrowing a current path in the semiconductor layer. A second current blocking layer may be formed on top of the semiconductor layer.

Abstract: A semiconductor light emitting device, such as a light emitting diode or laser, includes a substrate which is provided with a hole and a pn junction extending adjacent to and in parallel with the side wall of the hole. Thus, the side wall of the hole extends in a direction perpendicular to a main surface of the substrate. A pair of electrodes is provided such that current flows across the pn junction so that light emitted in a vertical direction which is perpendicular to the main surface of the substrate. The hole may be either a through hole or a bore hole. With the additional provision of a pair of resonators, there is provided a semiconductor laser.