Singlemode output power enhancement of InGaAs VCSELs by reduced spatial hole burning via surface etching

Completely singlemode MBE-grown selectively oxidised InGaAs-VCSELs with aperture diameters of up to 14 /spl mu/m have been fabricated using a self-aligned shallow surface etch. By choosing the growth position accordingly, a continuous variation of the aperture diameter across the wafer is achieved to optimise the surface etch to aperture diameter ratio. A record singlemode output power of 5.7 mW (30 dB SMSR) is obtained for a 5.8 /spl mu/m-aperture diameter, 2.8 /spl mu/m etch spot diameter device.