Study On Mismatch Epitaxial Of Gaas-Based Ingaasp Laser Materials And Device

In the past decade, information industry developed rapidly, and the optical fiber communication system are facing a new challenge. In the optical fiber communication system, the emitters and receivers contain many optoelectronic devices. Thus, the performance of optoelectronic devices directly affects the performance of the optical fiber communication system. By integrating multiple photovoltaic devices on a single chip, optoelectronic integrated circuit (OEIC) technology can not only make the device more miniaturized, but also reduce the overall power consumption. Improving the overall performance of fiber-optic communication systems is currently the focus of people’s attention.Semiconductor lasers are the essential devices in the fiber communication systems. InP-based optoelectronic devices are essential for optical communication and have shown great potential for long-distance fiber communication, such as lasers and detectors. Most of commercial1.55μm semiconductor lasers are InP-based InGaAsP lasers. Unsatisfactorily, some insufficient of InP substrates, such as high cost and frailness, limit some applications in several areas. GaAs substrates have many good performances, such as relatively low cost and good mechanical properties, which can make up for the inadequacy of InP substrates. Moreover, GaAs-based integrated circuit (IC) technology is relatively mature in comparison with that of InP-based IC. If GaAs electronic devices and InP-related optoelectronic devices are combined with GaAs substrates, optoelectronic integrated circuits could be realized easily, and the optical fiber communication systems can be made an important progress.The thesis is aimed at the InP/GaAs integration, and investigates the metamorphic growth of1.55μm InP laser structures on GaAs substrates. The details are listed as follow.1. By the MOCVD system, we investigate the epitaxial conditions of the InGaAs/InGaAsP multiple quantum wells (MQWs) laser. Through control of zinc source access time, we solve the problems of zinc source to the diffusion of the active region. We successful grow InGaAs/InGaAsP MQWs laser strtuactes on InP substrates, and fabricate the broad area emitter laser with200μm strip and500μm cavity length. At the roomtemperature and quasi-continuous wave (QCW) condition, the threshold current is700mA, and the single slope efficiency is0.15mW/mA.2. The thesis investigates the metamorphic growth of InP/GaAs. High quality heteroepitaxy is realized by employing a thin low-temperature (LT) InP buffer layer, thermal cyclic annealing (TCA) and strained-layer superlattice (SLS) are used to improve the quality of active layers crystal.3. We successful grow InGaAs/InGaAsP MQWs laser strtuactes on GaAs substrates by MOCVD system. From the DC-XRD spectra, the satellite peaks of the InGaAs/InGaAsP MQWs could be observed in the left and right sides of InGaAsP/InP epilayers peak. The ECV measurement shows that the hole concentration and electron concentration is1×1018cm-3in p-type and n-type InP cladding layers. The root mean squaresurface roughnesses the laser structure, as measured by AFM over10xl0μm2, is1.39nm4. We successful fabricate the broad area emitter laser whith50μm strip and500μm cavity length. At the roomtemperature and quasi-continuous wave (QCW) condition, the threshold current is476mA, and the single slope efficiency is0.15mW/mA. The output peak wavelength of light is1549.5nm and the vertical divergence angle was38°, when the injection current is700mA. Under the auto-current-control (ACC) mode, the device has been operating for more than2000hours at600mA and RT.5. We successful fabricate the ridge waveguide lasers with30μm stripe width and500μm cavity length. A threshold current of326mA under CW operation at RT has been measured for a device with30μm stripe width and500μm cavity length. Its threshold current density is2.07kA/cm2. Under QCW condition, the threshold current density is as low as1.2kA/cm2. Furthermore, the peak wavelength of1548.7nm and the FWHM of1.3nm are obtained for an optical spectrum which is taken at400mA under continuous wave (CW) operation. The characteristic temperature To is65K. Result of acceleration aging tests shows the device could operate more than80hours at85℃under CW condition. At room-temperature, the device has operated more than500hour and observer no degradation.6. We investigate the InGaAsP strain compensation MQWs structures, and successful fabricate InGaAsP strain compensation MQWs laers on GaAs substrates. The broad area bifacial laser is50μm strip and500μm cavity length. At the room-temperature and QCW condition, the threshold current is1260mA. The broad area coplanar laser is12μm strip and500μm cavity length. At the room-temperature and QCW condition, the threshold current is600mA.