Gain characteristics of In0.60Ga0.40As/In0.53Al0.20Ga0.27As superlattice active regions for vertical-cavity surface-emitting lasers

The results of investigation of the gain properties of 1300 nm vertical-cavity surface-emitting lasers active regions based on In0.60Ga0.40As/In0.53Al0.20Ga0.27As superlattices and threshold characteristics comparison of superlattices and highly lattice mismatched In0.74Al0.16Ga0.10As quantum wells are presented. The heterostructure of injection lasers with an In0.60Ga0.40As/In0.53Al0.20Ga0.27As superlattice was grown by molecular beam epitaxy. Mesa structure of injection lasers was obtained by selective liquid etching followed by the application of ohmic contacts. The formation of injection lasers with various cavity lengths is performed using the method of manually cleaving mirrors. The output characteristics were measured in a pulsed mode using a large area calibrated germanium photodiode. Spectral characteristics were measured using a spectrophotometer based on monochromator. The achieved threshold characteristics (modal gain about 40 cm–1, transparency current density about 650 A/cm2, internal optical losses about 8 cm–1) of injection lasers based on In0.60Ga0.40As/In0.53Al0.20Ga0.27As superlattices with low lattice mismatch InGaAs layers are comparable to previously presented lasers based on active regions with strongly strained In0.74Al0.16Ga0.10As quantum wells. The characteristic temperatures T0 and T1 were 60 K and 87 K for injection lasers with a cavity length of 1 mm. An increase in the frequency of small-signal modulation of vertical-cavity surface-emitting lasers and their temperature stability is associated with the use of highly strained In0.74Ga0.26As/In0.53Al0.25Ga0.21As superlattices. The proposed active regions based on InGaAs-InP superlattices have the potential to be used in the development of vertical-cavity surface-emitting lasers in the 1300 nm spectral range. The findings of this work can be applied in the realization of experimental species and optimization of modulation parameters for vertical-cavity lasers operating in the 1300 nm wavelength range.