Abstract: The present application provides an optical device and a method of fabricating the same. The optical device include a semiconductor stack structure, an anti-reflective film and a highly-reflective film. The semiconductor stack structure is configured to generate a laser beam and emit the laser beam from its front facet while receiving an electric current. The anti-reflective film is disposed on the front facet of the semiconductor stack structure and configured to increase the transmittance (reduce a reflectivity) of the front facet to the laser beam. The highly-reflective film is disposed on a rear facet of the semiconductor stack structure and is configured to reduce a loss (increase a reflectivity) of the laser beam transmitted to the rear facet. The anti-reflective film and the highly-reflective film respectively have refractive indices greater than 2, and the highly-reflective film has a thickness greater than that of the anti-reflective film.