Abstract

The high contrast ratio and planar emission geometry of vertical cavity surface emitting lasers (VCSELs) makes them attractive for application as sources in interconnection applications. As part of work on a Tbit/s ffee-space optoelectronic interconnect [1] we have fabricated top-emitting VCSELs in 8x8 arrays, emitting at 960nm wavelength. The ridge waveguide VCSEL devices are top-emitting, grown by metallorganic vapour phase epitaxy on an n-type GaAs substrate with an AlGaAs cavity with three central In₀₁₃Ga₀₈₇AS quantum wells, sandwiched between two distributed Bragg reflectors (DBR) of alternating GaAs and Al₀₉Ga₀₁As layers with linear heterointerface grading. 21 and 30.5 mirror pairs form the top (p-doped) and the bottom (n-doped) DBR, respectively. The device pitch is 250 μm and the whole VCSEL array occupies an area of 2.8x2.8 mm². The main DC characteristics of the VCSEL arrays were measured on wafer level. For an array with 64 devices with 10 μm diameter of the p-contact opening and 14 μm mesa diameter the values are as follows: mean threshold current 2.65±0.05 mA (±2%), mean threshold voltage 1.88±0.01 V (±0.5%) and output power of 1.25±0.02 mW (±1.5%) at 8 mA. The average peak power conversion efficiency is 6.3 %. The VCSELs emit at 956 nm with a maximum variation of 0.7 nm.

© 2000 IEEE