Optimization Design And Characteristic Analysis Of InP-based Multiple Quantum Well Ring Laser

Compared with semiconductor optical amplifier-based Mach-Zehnder interferometer(SOA-MZI) and nonlinear optical loop mirror(NOLM), semiconductor ring lasers(SRLs) have received increasing attention, because they can be fabricated without the need for cleaved facet or gratings for optical feedback. With in-depth development of the research, there has been a continually increasing interest in SRL applications, such as integrated light source, optical label switching, optical SRAM, and optical switch. Therefore, SRL has been regarded as a basic building block for constructing large scale photonic integrated circuits.In this thesis, we firstly designed the structure of AlGaInAs/InP multiple quantum well(MQW) ring laser, including material properties, waveguide structure, ring radius, and coupling gap. By analyzing the effects of the structural parameters on the device performance, a ridge waveguide with 2?m ridge width and 1.8?m etching depth was developed. Based on the wave equation and coupled-mode theory, the relationship between bending loss and ring radius and the influence of coupling gap on the coupling efficiency were simulated and analyzed. Considering the existing process equipment, a SRL with coupling gap of 1.0?m and radius of 350?m was designed, and the corresponding coupling efficiency was about 5%. Afterwards, the threshold current expression and its function of MQW structural parameters, which suitable for the case of circular SRL with one coupled straight waveguide, were derived from the oscillation condition of Fabry-Perot cavity laser. Furthermore, an equivalent SRL model was constructed utilizing a numerical device simulator ATLAS, and the effects of MQW structural parameters on the threshold current density of SRL were simulated with various operating temperatures. For the AlGaInAs/InP material system and device structural parameters adopted in this thesis, the optimal MQW structural parameters are M=3, dw=20nm and dB=10nm, respectively.Finally, depending on the characteristics temperature theoretical model, the temperature characteristics of SRL with various ring radiuses were analyzed. Based on the optimization design, a reasonable AlGaInAs/InP MQW ring laser with radius of 350?m was realized. The experimental results shown that the designed device, lasing at 1566.7 nm with side mode suppression ratio exceeding 20 d B, exhibited unidirectional bistability between the clockwise and the counterclockwise modes, thus confirmed the validity of the design considerations.