Optimization of oxide-confined vertical-cavity surface-emitting diode lasers
The performance of modern oxide-confined (OC) vertical-cavity surface-emitting diode lasers (VCSELs) is distinctly different than that of earlier VCSEL designs. As a result, hitherto known optimal VCSEL designs cannot be considered as the best ones any longer; they need new analysis to determine their optimal OC designs for their various applications. Therefore, in this paper, a comparative analysis of the room-temperature (RT) continuous-wave (CW) threshold operation of various designs of OC VCSELs is carried out using the 1.3 µm OC intra-cavity-contacted GaAs-based quantum-well (GaIn)(NAs)/GaAs VCSEL as a typical example. The analysis has been made with the aid of a comprehensive fully self-consistent three-dimensional optical-electrical-thermal-gain model. Depending on an application, different OC VCSEL designs have been found to be optimal. The lowest RT CW lasing threshold has been found to be achieved in the 1.5λ-cavity design with only one oxide aperture (for smaller active regions) or in the 3λ-cavity design with two oxide apertures (for larger active regions). On the other hand, to reach the single-fundamental-mode operation and/or longer lasing wavelengths, the 3λ-cavity OC VCSEL with one oxide aperture happened to be the best lasing design, especially for relatively large active regions.