The jet injecting aerodynamic window is a new type of aerodynamic window recently developed in the authors laboratory. An experimental study of the sealing performance and optic quality of the beam output for various sizes of the jet injector has been carried out. The optic behavior is measured with the Hartmann diagnostic apparatus, which can provide several parameters such as the peak to valley ratio and the rootmean square value of the wavefront, the Strehl intensity ratio, et al. Experimental result...