Three-terminal Bragg structure quantum well laser with large range wavelength tunability

It is suggested that by the use of a three-terminal device a practical means for the application of the required high electric field can be obtained. A novel quantum well with Bragg structure, useful for electric field-effect wavelength tuning, is proposed to reduce the screening effect. As in the case of the guided modes in a Bragg reflection waveguide, bound electronic states can exist in a quantum well structure with a semi-infinite periodic medium instead of a usual potential barrier. Since the bound state is very sensitive to the composite structure the energy level can easily be changed by varying the applied field. As a result, large range wavelength tunability can be achieved