Temperature characteristics of 1.16 μm highly strained GaInAs/GaAs VCSELs.

We demonstrated highly strained GaInAs/GaAs QW VCSELs emitting at 1.16 mum. The fabricated device shows a record low threshold current density and high efficiency in the 1.2 mum wavelength band. The VCSEL structure was monolithically grown on a (100) n-type GaAs substrate by a low-pressure metalorganic vapor phase epitaxy (MOVPE). The active region consists of 8 nm thick Ga0.64In0.36As TQWs separated by 25 nm GaAs barrier layers. The compressive strain of QWs is 2.3%. The threshold current is 3 mA for a 10 mum similar to10 mum oxide device, corresponding to a threshold current density of 3 kA/cm(2). We achieved the maximum output power of over 2 mW and a slope efficiency of 0.3 W/A at 25 degreesC, which are the record data for 1.2 mum band GaInAs VCSELs. The maximum CW operating temperature is 85 degreesC. The threshold current is almost constant in the temperature range of 20-70 degreesC which results from appropriate wavelength matching between the gain peak and lasing mode. The temperature dependence of the lasing wavelength is 0.07 nm/K. The details of their device fabrication and lasing characteristics are discussed.