摘要 |
<p>A method of laser-drilling a hole through a workpiece, such as an injector nozzle (40), into a cavity comprising drilling a hole (41) through the workpiece (40) with a laser (50), providing a fluid having laser-barrier properties in the cavity so that, when the hole (41) is open to the cavity, laserlight passing through the hole (41) is incident upon the fluid whereby the workpiece (40) across the cavity from the hole (41) is protected from the laserlight, and arranging that the fluid does not enter the laser-drillled hole (41) during the drilling process. Apparatus for performing the method is also described.</p> |