PURPOSE: To obtain the titled laser suitable for ring laser gyroscope by a method wherein a discharge outlet is provided in the neighborhood of the center of a laser fine tube, and anodes in the neighborhood of Brewster windows at both ends, respectively; then the discharge outlet is arranged at the center of the cylindrical cathode in a vacuum casing.

CONSTITUTION: The anode 5' is buried also in the neighborhood of the Brewster window 3' of the laser fine tube 1, anodes thus being provided in a total of two, and the discharge outlet 2" is arranged at the center of the anode 6, i.e., nearly at the center of the fine tube. The construction of other parts is almost the same as that of the conventional laser tube. This construction brings gas flows 12 and 12' due to DC discharge which direct to the cathode from the anodes 5 and 5' in symmetry, and therefore the variation in the frequency of a laser beam passing through the laser fine tube is cancelled. Accordingly, in the case of constructing the external mirror type ring laser gyro, a piece of laser tube is sufficient, and the structure and the adjustment of the device are simplified.