Single transverse mode active multimode interferometer InGaAsP/InP laser diode

A novel laser diode, in which the pumping area is increased by a multi-mode interference (MMI) coupler, is proposed to maintain single-lobe outputs up to high powers. Utilising active 1/spl times/1 MMI couplers between singlemode waveguides, up to 90% higher single-lobe and fibre-coupled output powers were obtained at 1.3 /spl mu/m.