One embodiment of a ring laser gyroscope discussed herein includes a cavity containing a gain medium having a first linewidth, a first plurality of reflective surfaces coupled to the cavity, and at least one medium exciter operable to excite the gain medium. The half shells combine on the molding path to form a closed mold. At the same time, along with the inner coating, the Cr diffusion layer is also applied to the MCrAlY-based bonding layer of the outer coating by chemical vapour deposition. A top guide, on the bottom guide, has guide pins that are movable in a vertical direction at positions corresponding to the first pins.