Northrop Grumman Systems Corporation

Litton Systems, Inc.

Carl Bathelt, Jr

David Barnett Hall

Samuel N Fersht

Robert A Mitchell

Shane Sammon

A ring laser gyroscope includes a first plasma shunt arranged to prevent the plasma from contacting a first mirror in the gain region and a second plasma shunt arranged to prevent the plasma from contacting a second mirror in the gain region. The first and second plasma shunts may comprise electrical conductors located in the respective mirror wells and arranged such that contact between the plasma and the electrical conductors quenches the plasma in the mirror wells and produces electrical currents that travels across the mirror wells. The electrical conductors may be formed as metallized strips arranged to extend across the mirror wells, or they may be formed from metal wires. The plasma shunts may alternatively comprise diversion passages formed in the frame and arranged such that the plasma fills the diversion passages and bypasses the mirrors.

Plasma shunting apparatus and method for ring laser gyroscope

An OFF state, maximum attenuation level, for an electro-optic attenuator/switch results when either a first or second control voltage is applied to the control input. An AC generator, coupled to the control input, generates minimum and maximum peak voltages that correspond to the first and second control voltages, respectively, so that the maximum attenuation level of the light beam being switched is provided by the electro-optic attenuator while either of the minimum and maximum peak voltages is applied to the control input. An ON state is achieved by introducing a voltage pulse with a magnitude corresponding to the minimum attenuation level. The ON voltage pulse is added to the square wave. This permits operation of the electro-optic switch in a normally OFF state without requiring a DC bias voltage.

Electro-optic switching apparatus not requiring DC bias

A fiber optic seismic sensor includes a central support assembly formed of a metal such as aluminum. A support plate has an inner portion retained within the central support assembly and an outer portion that extends beyond the central support assembly. A pair of hollow cylindrical substrates are mounted in axial alignment on opposite sides of the outer portion of the support plate with the central support assembly extending through the centers of the substrates. The central support assembly comprises a first central support member having a cavity in one end, and a second central support member having a projection extending therefrom and arranged to be received within the cavity in the first central support member. The support plate includes a passage arranged to receive the projection such that the inner portion of the support plate is retained between the first and second central support members. A first spiral-wound optical fiber coil is formed on an outer end of the first substrate, and a second spiral-wound optical fiber coil is formed on an outer end of the second substrate. An interferometer includes the first spiral-wound optical fiber coil in a first leg and the second spiral-wound optical fiber coil in a second leg. Acceleration along an axis perpendicular to the planes of the optical fiber coils causes a deflection in the support plate, which changes the pathlength difference between the legs of the interferometer.

Growing community of inventors

Simi Valley, CA, United States of America

Carl Bathelt, Jr