Surface-emitting laser diode with vertical GaAs/GaAlAs quarter-wavelength multilayers and lateral buried heterostructure

Abstract
Threshold current of 2 mA at room temperature cw operation is realized in a vertical distributed feedback surface-emitting laser diode with lateral buried heterostructure (LBH). In this LBH structure, the vertical distributed feedback active region (AlGaAs/GaAs multilayer) is entirely surrounded with n- and p-type AlGaAs cladding layers for minority-carrier confinement. The far-field angle is 7°. The beam shape is nearly circular. However, the lasing spectrum is broad (2–3 nm) compared with the conventional edge-emitting laser. Major differences between the surface-emitting laser diode presented here and the conventional edge-emitting laser diode are discussed.