Abstract: The continuous wave laser oscillation of optically pumped metastable Ar laser was observed. By employing a narrow linewidth diode laser based on volume Bragg grating as the pump source and He-Ar RF capacitive discharge plasma at 0.08 MPa as the gain medium, the power of 912.3 nm output laser was measured to be 0.22 mW from a laser cavity based on a longitudinally double-pass-pumped configuration.