Abstract

It has recently become possible to manufacture laser media consisting of thin layers that are each thinner than the wavelength of light. The semiconductor versions are multiple-quantum-well lasers, also called surface emitters. Other lasers that can be built with this structure are stoichiometric lasers. It is shown that a ring laser can be made with this structure in a configuration such that the spontaneous (laser) noise is interferometrically subtracted and hence not detected. For applications, such as rotation-sensing of magnetic fields, it is necessary to eliminate the strong coupling between counterpropagating waves owing to the nature (thin films) of the emitter. Solutions to this problem involving either intracavity or extracavity passive elements are presented. Other applications require the laser to be unidirectional. This goal can be achieved by adding a single reflecting layer to the active stack of emitters.

© 1990 Optical Society of America