Method and device for etching patterns inside objects

A system for forming an etched pattern on an interior surface of a hollow object, the system comprising:

• a laser system comprising:
• a laser source,
• a focusing lens, and
• a laser head positioned distally from the laser source along a longitudinal axis, the laser head including a reflector,
• wherein the laser system is configured to change a positional relationship between the reflector and the focusing lens to accommodate a change in a distance between the reflector and the interior surface of the hollow object so that a focal point of the laser system remains focused on the interior surface;
• and
• a motion control system configured to provide rotation and translation about the longitudinal axis for one or both of the laser system and the hollow object based on a pattern to be etched, and adjustment of the positional relationship between the reflector and the focusing lens of the laser system, wherein the adjustment is inversely proportional to the distance between the reflector and the interior surface of the hollow object.