Transverse modes of gain-guided coupled-stripe lasers: External cavity control of the emitter spacing

Abstract
By means of an external grating cavity, the dispersion relation of the transverse modes of gain‐guided coupled‐stripe laser diodes is determined. The parabolic relation obtained indicates (despite the stripes) a relatively flat gain profile similar to a broad area laser. Accordingly, higher order transverse modes are possible and are demonstrated with near and far fields exhibiting one and two emitters per stripe.