GaInAsP/InP Surface Emitting Injection Laser with Buried Heterostructures

Abstract

The first surface emitting (SE) injection laser (λ≃1.2 µm) with buried structure has been realized from the GaInAsP/InP system. The circular active region of 50 µm in diameter is buried by employing the LPE growth of i) maskless planar buried heterostructure (PBH) and ii) conventional masked buried heterostructure (BH). The near field was of a circular pattern of about 50 µm in diameter and it has been confirmed that the lasing occurred in the direction perpendicular to the surface by comparing output powers from the surface and the edge. The lowest threshold current of the BH SE laser was 520 mA (26 kA/cm2) at 77 K. The PBH SE laser had somewhat higher threshold than the BH SE laser at the present stage, but the PBH structure seems to be suitable for the SE laser because it has been found that it is easy to grow flatter surfaces.