GaInAs/InP planar buried heterostructure (PBH) lasers with semi-insulating blocking layers were grown in an ‘all’ atmospheric OMVPE system. These layers had current thresholds as low as 35 mA and differential quantum efficiencies of ≃16% at a wavelength of 1.64 μm. The maximum power output was 80 mW pulsed and 8mWCW.