The resistivity achieved is up to(1-2)×108 Ω.cm for D2+ bombarded GaAs single crystal chips from the room temperature to 600℃ so long as the annealing temperature is kept below 200 ℃. The near field pattern, spectral, frequency response and degradation characteristics for the isolated stripe geometry lasers made of D2+ bombarded (QaAl) As/GaAs DH chips are almost the same as those of H+ bombarded lasers.