Abstract: An orifice disc for a fuel injector includes two orifices that provide a desired interaction between two fuel flows to increase fuel atomization and improve combustion performance. The orifice disc includes a first orifice and a second orifice that are disposed at an interaction angle relative to each other. The orifices are orientated relative to each other such that fuel flow exiting the outlets impinges on each other to further reduce the size of fuel droplets. Large dramatic changes in momentum caused by the impingement of fuel flows disintegrates fuel droplets into much smaller finer fuel droplets that provided enhanced atomization.

Abstract: Preferred embodiments of a system and methods to deliver different magnitudes of laser power density to a work piece while maintaining a constant focusing spot size are described. In particular, the system includes a laser, an optical focusing assembly and an overlay. The overlay receives a laser beam having a perimeter at a first magnitude of power and transmits the laser beam to the optical focusing assembly at about the same perimeter and at a magnitude lower than the first magnitude. In a preferred embodiment, the overlay can include an optically neutral blocking lens or a neutral density filter. A method of laser machining an orifice at a suitable average power density sufficient to machine the orifice with reduced heat affected zone, spatters, soots or recasts is described. A method of providing a focusing spot size of a generally constant effective area by a laser machining system is also described.