Asymmetric Multi-Quantum-Well Semiconductor Optical Amplifiers

• Main Authors: Sheng-Che Yen, 顏聖哲
• Other Authors: Tao-Yuan Chang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/23275540494410197159

碩士 === 國立中山大學 === 光電工程研究所 === 90 === Traveling-wave semiconductor optical amplifiers（TWSOAs）of symmetric and asymmetric multiple quantum wells（MQWs）have been implemented by using angled-facet structures. The asymmetric MQWs structures are designed to increase the wavelength range of the gain spectrum. The angled-facet structures, which can suppress gain ripple from FP resonance, are of 3mm-wide and 700mm-long ridge waveguides, and of different angles（q）at 3o, 5o, 7o, and 9o. From Marcuse’s model, the calculation shows that the angled-facet structures have reflectivities lower than 10-4. We have also developed a single-trench process to fabricate the angled-facet TWSOAs. The l=1.55mm asymmetric structure, which shows a low epitaxial quality of large leakage current, is not suitable for SOA application. For the l=1.3mm asymmetric structure, the threshold current（Ith）at q=0o was 22.5mA, while at q=7o the Ith increased to 45mA. We have also measured the spectrum below threshold current. The differences between FP resonance peak and valley become smaller at larger q. We estimated that the reflectivity is about 0.2 at 5o. The results show that the reflectivity was decreased by angled-facet structure.