Particle damage protection for high power CO2 slab laser mirrors
AssigneeCoherent, Inc.
InventorGongxue Hua
Life of this patent
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Abstract
A CO2 gas discharge laser includes elongated planar live and ground electrodes vertically spaced and electrically insulated from each. The electrodes are spaced apart by ceramic spacer strips arranged along the edges of the electrodes. An auxiliary electrode is located at each end of the live electrode, co-planar with the live electrode, longitudinally spaced part from the live electrode vertically spaced apart from, but electrically connected to, the ground electrode. The auxiliary electrode has two raised portions spaced apart by a distance less than the distance between inside edges of the ceramic strips. The raised portions of the auxiliary electrode prevent erosion of the ceramic strips by laser radiation generated in the resonator when the laser is operating.
Claims14
A gas discharge laser driven by radio frequency (RF) power, comprising:
- first and second elongated planar discharge-electrodes arranged vertically spaced apart and parallel to each other, and electrically insulated from each other with the first electrode functioning as a live electrode and arranged to receive the RF power from a source thereof and the second electrode functioning as a ground electrode, with the discharge electrodes being spaced apart by first and second electrically insulating spacer strips having first and second opposite ends and arranged along opposite edges of the electrodes with inside edges thereof laterally spaced-apart by a first distance, the spacer strips having a height which determines the vertical spacing of the live and ground electrodes;
- first and second mirrors forming a laser resonator extending longitudinally through the space between the discharge electrodes, such that when a discharge is created in a lasing gas between the discharge electrodes when the first electrode receives the RF power, laser radiation circulates in the laser resonator;
- and
- a planar extension block at each end of the first electrode, longitudinally spaced part from the first electrode, vertically spaced apart from the ground electrode and electrically connected to the second electrode, the extension block having two raised portions thereon having a height about equal to the height of the spacer strips and laterally spaced apart by a second distance less than the first distance, whereby erosion of the insulating spacer strips by the laser radiation is minimized.
The gas discharge laser of FIG. 7, wherein the spacer strips have a reduced width at each end thereof, configured to accommodate the raised portions of the extension block.
A slab laser comprising:
- a housing containing a laser gas;
- a pair of elongated, rectangular, planar electrodes, positioned within the housing in spaced apart, face to face relationship, one of said electrodes operating as the hot electrode and the other as the ground electrode;
- a pair of mirrors aligned with opposite ends of the electrodes and defining the laser resonator and wherein the length of the hot electrode is less than the length of the ground electrode and is positioned so that the opposite ends of the hot electrode are spaced farther away from the mirrors than the ends of the ground electrode;
- and
- a pair of metal extension blocks positioned between the respective opposite ends of the hot electrode and the associated mirror, each said extension block being spaced from the end of the hot electrode in the length direction and positioned in face to face relationship with the ground electrode, said extension blocks being connected to ground so that no laser discharge occurs between the ground electrode and the extension blocks.
Dependencies are inferred from the claim text.