Abstract: A semiconductor laser having opposed end surfaces with an optical reflective means on the surface of at least one end surface has fundamental lateral mode selectivity. The laser has an optical waveguide that extends from one end surface to the other. The optical reflective means may be an electrical insulation layer on the end surface with a reflective stripe on the insulation layer and having a width in the lateral direction less than that of the spatial width of the fundamental lateral mode in the absence of the reflective stripe. Alternatively, the selectivity means can be an antireflection layer on the end surface with a stripe opening in the antireflection layer having a width in the lateral direction less than that of the spatial width of the fundamental lateral mode in the absence of the antireflection layer. The opening in the antireflection layer is formed by placing a wire close to the end surface and evaporating the antireflection material onto the end surface.

Abstract: This invention relates to a method of aligning the core of a thin optical fiber with a light emitting optical device. Prior to alignment a thin, continuous high index of refraction layer is formed on a stripped end segment of the optical fiber. The layer is formed by applying a solution of a volatile solvent and high index of refraction polymer to the stripped segment and evaporating the solvent before beading of the polymer solution occurs. The core of the fiber can then be aligned with the light emitting optical device by observing light exit the optical fiber.