Total gain of InTlAsSb quantum dot structures

This work studies the total gain of the InTlAsSb quantum dot structure, which is not studied earlier. Adding thallium to structures makes it emit at larger wavelengths. The nonlinear effect of the injected signal power is examined for three quaternary thallium structures: In0.85Tl0.15AsSb, In0.93Tl0.07AsSb and In0.97Tl0.03AsSb. The gain peak was increased by four times and the wavelength was shifted to longer one for the In0.97Tl0.03AsSb quantum dot (QD) structure. This quaternary QD structure extends the emission wavelength to more than 12 μm which is important in long-wavelength infrared applications. The nonlinear behavior of these QD structures is also addressed. It is shown that the structure In0.97Tl0.03AsSb has a deeper spectral hole burning which is adequate for nonlinear signal processing applications.