Patent ID: 7469557

Claim:
A method for forming a capillary column comprising the steps of providing a glass rod, scribing a recessed pattern on an exterior surface of the glass rod by focusing and indexing at least one laser along the axis of the rod while the rod is under rotation, providing a thin walled glass sleeve that is slightly larger in bore than the glass rod, inserting the patterned glass rod within the glass sleeve and fusing the glass sleeve to the exterior surface of the glass rod while not filling in the recessed pattern by rotating the assembly and defocusing the laser focal point to a location than on the assembly outer diameter so as to just melt a portion of the thin walled glass sleeve that is adjacent non-recessed portions of the glass rod and fusing the melted portion of the thin walled glass sleeve to non-recessed portions of the glass rod, thereby defining a capillary column in the shape of the recessed pattern.