A method of welding an axle housing surface to a blank surface includes generated heat in one of the two components. The power supply voltage to each macro is first assumed to be nominal. The substrate includes at least one window wherein is housed the electronic component, the adhesive layer maintains the conductive layer on the substrate, the conductive layer extends partially into the window’s surface so as to form at least one electric contact whereon the electronic component is connected. The distances between an end of each of the sub-electron emitters away from the cathode electrode and a sidewall of the through-hole are substantially equal. The beam splitter 4 by which the incident light beam is wave-separated and wave-combined, is arranged with a little inclination from the vertical to the incident light beam. By tilting a focusing lens for pumping light with respect to the optical axis of the pumping light, the astigmatism is compensated.