Hideaki Iwano

Transverse Mode Characteristics of a DBR-Surface Emitting Laser with Buried Heterostructure

Distributed Bragg reflector (DBR)-surface emitting lasers (SELs) with buried heterostructure (BH) are fabricated with the combination of metal-organic chemical vapor deposition (MOCVD), electron cyclotron resonance (ECR) dry-etching and liquid phase epitaxial (LPE) regrowth techniques. Low threshold and stable fundamental lateral-mode characteristics are realized by the optimum design of the cavity diameter and refractive indices. Other important characteristics such as polarization characteristics, series resistance and thermal resistance are also discussed.

Low-threshold surface-emitting laser diodes with distributed Bragg reflectors and current blocking layers

AlGaAs/GaAs surface‐emitting laser diodes (SELDs) with distributed Bragg reflectors (DBRs) and current blocking layers are fabricated with the combination of a two‐step epitaxial growth and the reactive ion beam etching (RIBE) technique. An Al0.1Ga0.9As/Al0.7Ga0.3As multilayer and an amorphous silicon (a‐Si)/silicon dioxide (SiO2) multilayer are employed for the lower and upper mirrors, respectively. The active region has a 5×5 μm or 4 μm φ area and a 0.8 μm thickness. The minimum threshold current is 3.3 mA under pulsed condition and 4.1 mA under continuous wave (cw) operation at 12 °C with junction‐side‐up configuration. Stable single longitudinal mode is observed, and far‐field pattern (FFP) indicates higher transverse mode operation.

Effect of cavity size on lasting characteristics of a distributed Bragg reflector‐surface emitting laser with buried heterostructure

Transverse‐mode characteristics of the distributed Bragg reflector‐surface emitting laser diode with buried heterostructure were investigated as a function of the cavity size. Stable, fundamental transverse‐mode operation was achieved for cavity openings of 4 μm in diameter and smaller. The effect of cavity size on threshold current and polarization characteristics is also discussed.

GaAlAs laser diodes with metalorganic chemical vapor deposition grown ZnSe layer for injection blocking and optical confinement

A transverse mode stabilized GaAlAs laser diode which includes a ZnSe layer for the waveguide has been developed. The double heterostructure of the GaAlAs laser is formed by low‐pressure metalorganic chemical vapor deposition (MOCVD), and a ZnSe layer is grown by adduct‐source MOCVD in order to block the injection current and change the real refractive index in the lateral direction. The fundamental transverse mode oscillation of more than 15 mW is obtained with a low threshold current of 28 mA and a high quantum efficiency of 76%. An output power as high as 25 mW is achieved.

Selectively embedded epitaxial growth of ZnSe by low-pressure MOCVD using dimethylzinc and dimethylselenium

Abstract Selective growth of ZnSe layers embedded flatly over a ridged GaAs substrate, whose ridge-stripes are covered with SiO2 films, has been achieved by low-pressure MOCVD using dimethylzinc (DMZn) and dimethylselenium (DMSe) as source materials. When the gas pressure is less than 50 Torr and the (DMSe)/(DMZn) mole ratio is less than 6, selective area growth is realized. On the other hand, to bring about a smooth-flat surface for embedded growth requires a minimum substrate temperature of 600°C. From these results, we discuss a selective growth mechanism of ZnSe. Furthermore, a transverse mode stabilized AlGaAs/GaAs laser diode with a low threshold current of 30 mA and a high external differential quantum efficiency of 80% has been obtained by a self-aligned fabrication process using a selectively-grown ZnSe layer for injection blocking and optical confinement.