.A novel coupled quantum well with large negative electro-refractive index change and low absorption loss[J].Optoelectronics Letters,2007,3(4):246-247 A novel coupled quantum well with large negative electro-refractive index change and low absorption loss XUZhi-Xin CollegeofScience,ZhejiangUniversityofScienceandTechnology,Hangzhou310023,China Abstract:       In order to solve excessive insertion loss and low on/off ratio in quantum well reflection-type waveguide optical switches,a novel InGaAs/InAlAs coupled quantum well structure is proposed. In the case of low applied electric field (F=19 kV/cm)and low absorption loss (α≈ 61.2 cm-1), a large negative field-induced refractive index change ( △ n=-0.0134) is obtained in the novel coupled quantum well structure at the operating wavelength ( λ =1550 nm). The value is larger by over one to two order of magnitude compared to that in a rectangular quantum well (RQW) on the above same work conditions. Hits: 3657 Download times: 190 View Full Text    Download reader