Abstract: A method and apparatus for stabilizing the scale factor of a fiber optic gyroscope in which a superluminescence diode or broadband multimode laser comprises the light source. The emission bandwidth injected into a fiber end from the light source is limited to a considerably narrower transmission bandwidth within the wavelength band of the intensity characteristic of the light by a narrowband optical filter. The temperature at the filter is measured, and the transmission bandwidth quickly corrected by means of a pre-calibrated look-up table when optical interference filters are employed. The readjusted wavelength value is used for scale factor calculations.

Abstract: A process for producing a laser cathode by vacuum coating provides well-controlled, slow layer growth in the presence of the laser gas at a total pressure of up to 5.times.10.sup.-4 mbar. Such process includes laser gas atoms in the cathode layer. Without interruption of the vacuum, the coated cathode is moved into a (second) position and laser gas is introduced under slight pressue against the cathode coating by means of a nozzle. At the same time, a number of discharge cycles are initiated via the electrically conductive base of the cathode basic element and an electrode, arranged concentrically with respect to the nozzle, having the effect of premature sputtering-off to cause a levelling of the current density and a further inclusion of inert gas atoms in the Al coating. After a number of discharge cycles, a small amount of oxygen may be added to form an Al.sub.2 O.sub.3 passivation layer before flooding of the recipient.