Long-wavelength vertical-cavity lasers

We report on three novel vertical cavity laser (VCL) structures for 1.55μm operation. Two of the VCL structures utilize an n-type GaInAsP/InP Bragg mirror combined with an Al(Ga)As/GaAs mirror using either wafer-fusion or metamorphic epitaxial growth. The third VCL employs two wafer fused AlGaAs/GaAs mirrors, in which lateral current confinement is obtained by localized fusion of the p-mirror. All three VCLs use strained GaInAsP quantum wells as active material and achieve continuous-wave (CW) operation at room-temperature or above. The single fused VCL operates up to 17°C and 101°C in continuous-wave and pulsed mode, respectively. The monolithic VCL-structure with a metamorphic GaAs/AlAs n-type mirror uses a reversed biased tunnel junction for current injection. This laser achieves record high output power (1mW) at room temperature and operates CW up to 45°C. The double fused VCLs with a 10×10μm 2 active area operate CW up to 30°C with threshold current as low as 2.5mA and series resistance of 30 Ohms. The emission spectra exhibit a single lasing mode polarized with 30 dB extinction ratio and a spectral linewidth of 150 MHz.