High-efficiency combined laser and photodetector in a monolithic integrated-optics module utilizing coupled waveguides

An integrated structure was made containing a laser and a photodetector, with a high transmission coefficient of the optical power, in a monolithic module utilizing an AlGaAs/GaAs heterostructure forming a system of coupled waveguides. Efficient operation of the laser having a broad contact was achieved by the presence, within its active part of regions of alternating length. Variation of the lengths of the elements of a line of slots with vertical walls, used as a resonator mirror, made it possible to vary the coefficient of coupling between the laser and the photodetector from practically 0 to 100%.