Creation of buried type heterostructures for microwave laser diodes
Complex physicotechnological studies of overgrown messtrip structures with a channel in the substrate, etching of the mesa, and repeated overgrowing of the zinc selenide with an insulating layer were carried out. Electron microscopic studies of the planarity of heterointerfaces between the substrate and epitaxial layers were carried out. The atomic structure of GaInAsP/InP epitaxial layers was studied by transmission electron microscopy. Using secondary ion mass spectroscopy (SIMS), we analyzed the profiles of the epitaxial layers of the heterostructure. Layers of a given composition In0,78Ga0,22As0,68P0,32, corresponding to a laser wavelength of 1.3 μm, were obtained. For the first time, a technique has been developed for creating laser diodes with a channel in the substrate, with etching of the messtrip structure and overgrowing with a layer of zinc selenide. This technique makes it possible to create laser diodes both with optical limitation of laser radiation and with limitation of the current flow along the laser strip. The process of etching the layers of the pn junction between laser strips, and overgrowing by zinc selenide on the surface of the etched structure, was first developed. This allowed using the LPE method to create heterostructures for laser diodes operating in the microwave range up to 10 GHz. The possibility of creating and operating laser diodes of this design and technology is shown. The volt-ampere, watt-ampere and spectral characteristics of laser diodes are investigated. A domestic technology is proposed for creating a microwave laser diode on a heterostructure with a channel in the substrate and repeated overgrowing of zinc selenide. The prospects of using laser diodes overgrown with an insulating layer of zinc selenide to create high-speed devices are shown.