This paper reports the experimental researches on impurity free vacancy disordering (IFVD) of the InGaAs/GaAs strained quantum well capped by a SiO 2 film and the suppression effect on IFVD with a SrF 2 film. This technology was applied to ridge waveguide InGaAs/GaAs/AlGaAs strained quantum well lasers and fabricated window structure lasers with nonabsorbing mirrors. The maximum output power is 340 mW for 3 μm width ridge waveguide lasers with windows. Compared with that of the conventional quantum well lasers, this maximum output power has an increase of 36%. The emission wavelength is 978 nm and FWHM is 1.2 nm at 100 mW. The far-field angles are 7.2° and 30° in junction-parallel and perpendicular directions, respectively.