A liquid ejection apparatus including: a first casing; a second casing; and a controller, wherein the first casing is movable between a close position close to the second casing and a distant position farther from the second casing than the close position, the first casing accommodating a head having an ejection face. The coupling device has at least one movable entraining element which is brought in contact with an opposite element located on the shaft door leaf. The phasor element is configured to adjust or control an optical path length of the laser light between the laser and the cavity coupling mirror by adjusting or controlling a density of the gas medium within the phasor volume. This permits for the first time the insertion or adhesive bonding of ceramic abutments into implants made from titanium oxide or other metallic materials. The shared pole has a recess on the top surface. The method also includes removing, using an in-situ etch, a portion of the III-nitride structure to expose a regrowth region and regrowing a III-nitride material in the regrowth region.