Computer simulation of tuned and detuned GaInNAsSb QW VCSELs for long-wavelength applications

Ga0.62In0.38N0.023As0.95Sb0.027/GaN0.025As0.975 quantum wells (QWs) used in standard GaAs-based GaInNAsSb/GaNAs vertical-cavity surface-emitting diode lasers (VCSELs) exhibit at room temperature (RT) the highest optical gain for the 1422 nm wavelength. Its RT continuous-wave threshold current for the 5 μm device is as low as only 0.68 mA. An increase in the QW active region temperature by about 100 K has been found to be followed by a shift of the gain spectrum of the above QW to the 1500 nm range. Therefore, a comprehensive computer simulation has been used to verify a possibility to highly detune GaAs-based GaInNAsSb/GaNAs VCSELs from the wavelength of 1422 nm to 1500 nm, closer to the wavelength used in the third generation of the fibre optical communication. Such a temperatureenhanced RT CW lasing operation of the 1500 nm VCSEL, with an active region identical to that of the 1422 nm one and the cavity properly re-designed for the 1500 nm wavelength, has been found to be reached at the threshold current as many as 17 times higher than that of the 1422 nm VCSEL.