We present data on strong carrier‐induced antiguiding present in strained‐layer InGaAs‐GaAs‐AlGaAs lasers. We calculate a value of 12.9 for the PetermannKfactor, and a corresponding antiguiding factor ofb=6.4. The magnitude of the carrier‐induced index depression in the well is estimated to range with drive current from 0.032 to 0.41. In all cases, the antiguiding is much stronger than reported for similar GaAs‐AlGaAs lasers. In addition, we show that emission from short cavity devices occurs from two distinct transitions, with emission from the GaAs barriers contributing a single peak to the far field, and emission from the InGaAs well contributing two lobes. The result is a three‐lobed far‐field pattern at laser threshold of the GaAs barrier emission.