Influence of polarization induced electric fields on the wavelength and the refractive index of intersubband transitions in AlN/GaN coupled double quantum wells.

The influence of polarization induced electric fields on the wavelength and the refractive index of intersubband transitions (ISBTs) in AlN/GaN coupled double quantum wells (CDQWs) has been performed by solving Schrödinger and Poisson equations self-consistently. It is found that the intersubband refractive index change of the ISBT between the ground state and the second excited state (1_odd-2_odd ISBT) increases, while that of the ISBT between the ground state and the third excited state (1_odd-2_even ISBT) decreases with the increase of the polarization induced electric fields. The maximal intersubband refractive index change of the 1_odd-2_odd ISBT can be up to 0.142. The results are finally used to discuss the prospects of nitride quantum wells for electric-optical modulation via cross-phase modulation operating within optical communication wavelength range. [ABSTRACT FROM AUTHOR]