Long-wavelength VCSELs with InP/air-gap DBRs

We demonstrate novel electrically pumped 1300 nm and 1550 nm VCSELs with two InP/air-gap DBRs. The active regions comprise conventional InGaAsP multiple quantum wells. A tunnel junction is placed between the active region and top DBR to convert electrons into holes, thus minimizing the use of p-type material in the structure to reduce the free-carrier loss and achieve current confinement. The whole structure was grown in a single growth run by low pressure MOCVD. For both 1300 and 1550 nm emission wavelengths, air-gap DBR VCSELs exhibit roomtemperature, CW threshold current density as low as 1.1 kA/cm 2 , differential quantum efficiency greater than 30%, and CW operation up to 85°C. The single-mode output power was 1.6 mW from a 1300 nm VCSEL with a 6.3 μm aperture; and 1.1 mW from a 1550 nm VCSEL with a 5.7 μm aperture under room temperature CW operation