Abstract: Disclosed herein is a Solid State Split-Gain Multioscillator Ring Laser Gyroscope comprising, in a preferred embodiment, a solid state Nd:YAG crystal body defining a non-planar resonator path. Magnetic sources are provided which effectuate the Split-Gain Selective Mode Suppression Phenomena. Total internal reflection along facets of the crystal or glass allow reduced cost during manufacture of the Gyroscope. An alternative embodiment includes a solid state active medium on a chip, allowing the resonator path to be primarily lying in a glass monolithic compact solid state frame.

Abstract: A path length controller for a ring laser gyro wherein the path length is dithered by dithering of one or more of the mirrors and the mirror or mirrors are controlled by a servo which is selectively biased in response to the servo signal to keep the mirror or mirrors in a position to support the largest amplitude of the principal mode of laser oscillation.

Abstract: The invention comprises a tachometer for aircraft for determining engine operating parameters from magneto signals from right and left magnetos. A signal conditioning circuit receives ignition signals from at least one magneto and modifies the ignition signals to provide a right and left train of input pulses for the microprocessor. The microprocessor follows a stored program to develop filtered quantitites depicting right rpm, and left rpm for respective right and left engines, or right and left magnetos of a single engine. The maximum rpm achieved during operation is also stored, along with the difference between the right and left rpms, the change in rpm over a period of time, and average rpm of two engines. A mode switch selects from right rpm, left rpm, maximum rpm, difference rpm, change in rpm over time, and average rpm for display on the display means. A method for calculating highly accurate engine RPM is disclosed.