A new stripe-geometry double heterojunction laser with internally striped planar (ISP) structure

A new type of stripe-geometry double heterojunction laser is proposed. The laser has internally striped planar (ISP) structure. The lateral current confinement is realized by using the difference of V-I characteristics between n-p-p-p and n-p-n-p structures. The ISP structure is made with both succesive solution growth techniques and selective diffusion techniques. Both near- and far-field patterns show single transverse-mode oscillation in the laser with 3-µm stripe width. The smallest active area of 2.5 µm (horizontal) × 0.6 µm (vertical) has been obtained. The transverse beam spreadbetween 50% peak intensity points is 30°. The polarization of laser emission is TE mode. The lowest threshold current obtained is 135 mA for the sample with 3-µm stripe width and 150-µm cavity length.