GaAs/GaAlAs单量子阱电光吸收和光调制

GaAs/GaAlAs Single Quantum Well Electroabsorption and Light Modulation

制作并研究了GaAs/GaAlAs分别限制单量子阱台面条形单模波导电致吸收光调制器。量子阱宽度为100A,长度为700μm的器件,当传输光波长为8650A时TE偏振最大调制深度(开关比)为29.7dB,插入损耗吸收分量为3dB;TM偏振最大调制深度为28.5dB。用2V电压幅度可以得到15dB的开关比。光电导谱的测量表明,偏压从+0.5V变到-7V时吸收边的红移为600A,即量子阱中室温激子的共振吸收峰移动了96meV。单阱高场条件下首次观察到了导带第二能级电子和价带第一能级空穴间激子的共振吸收线的出现,增强和移动。

GaAs/GaAlAs graded barrier single quantum well single mode ridge waveguide electroabsorptionmodulators were fabricated and investigated. For a modulator with quantum wellwidth of 100A and device length of 700μm, the on/off ratio of 29.7 dB, absorption fraction ofthe insertion loss of 3 dB were obtained for TE polarized light with wavelength of 8650A. ForTM polarization,the on/off ratio was 28.5dB. Photocurrent spectra exhibited a red shift of600A of the absorption edge by the bias valtage variation from+0.5V to -7V, correspondingshift of the exciton resonance peak is 96 meV. The appearance,enhancement and shift of anew exeiton resonance absorption peak was observec for the first time in the single quantumwell at high voltages,which may be attributed to the excitous composed of the electrons in thesecond quantum energy level and the holes in the first quantum energy levels.