Electroabsorption Modulation Based on Intersubband Transitions

This paper describes a study of the scope for using intersubband transitions as a basis for electroabsorption modulation of 1550 nm wavelength light. Intersubband absorption (ISBA) in the 1550 nm wavelength range in deep modulation doped In_0.53Ga_0.47As/AlAs quantum wells (QWs) is shown to be sufficiently strong to achieve an acceptable modulation depth of the optical carrier in a long waveguide device. The absorption strength decreases rapidly and almost linearly with increasing applied field strength, desirable attributes for a waveguide electroabsorption modulator.