Abstract: A system, circuit and method are disclosed for operating an RLG off-mode-peak to avoid exciting undesirable transverse modes. An alternate PLC operating point can be used to bias the optical path length of the RLG to an appropriate side of an ideal integer number of wavelengths, and thus avoid exciting the undesirable transverse modes. Although this alternate PLC operating point is not perfect with respect to establishing an integer number of wavelengths, this operation provides acceptable performance of the RLG's (in particular, short length path RLG's), and acceptable margin can be established relative to variations in the PLC set points involved. For example, a PLC loop can be used to dither about this operating point as a discriminate to allow closed loop control of the path length. Also, a PSSD control architecture can be used to establish and maintain a requisite path length over relatively wide variations in operating temperature.

Abstract: A ring laser gyroscope is described which includes a laser cavity configured to provide an optical laser path for a pair of counter-propagating laser beams, an optical sensor configured to receive a portion of the energy from the counter-propagating laser beams, and a unit configured to receive outputs from the optical sensor. The unit is configured to utilize the output to generate at least a residual path length control signal, a laser intensity monitor signal, and readout signals.

Abstract: An oxygen diffusion barrier is used to maintain a purity level of lasing gas in a ring laser gyroscope or other gas discharge device. The oxygen diffusion barrier reduces a release of contaminate gases into a cavity of the ring laser gyroscope and/or absorbs the contaminate gases in the cavity. The oxygen diffusion barrier may be formed on walls of the cavity before or after assembly of the ring laser gyroscope. Alternatively, a material may be applied to inside walls of a cathode mounted on a block of the ring laser gyroscope to maintain the purity level of the lasing gas. As a result of maintaining the purity level of the lasing gas, the ring laser gyroscope operates more efficiently.