Transverse mode characteristics of a high power 1.3µm GaInAsP/InP buried crescent laser by the use of a dry etching process is described. With this technique, a single transverse mode (STM) yield as high as 95% was achieved. Transverse mode stability was confirmed after 1000 h aging at 50, 20 mW. A coupling efficiency into a single mode fiber as high as 63% was obtained.

Mesa structures have been investigated to optimize a buried-heterostructure (BH) for a GaInAsP/InP surface-emitting (SE) laser regrown by metalorganic chemical vapor deposition (MOCVD), and it has been found that a square mesa top pattern of which the sides are at an angle of 45 to the 011 orientation is suitable. A 1.3-µm GaInAsP/InP square buried heterostructure (SBH) SE laser with this mesa structure has been demonstrated and low-threshold CW oscillation (threshold current Ith=0.45 mA) at 77 K and low-threshold room-temperature pulsed oscillation (Ith=12 mA) have been obtained.