Matches 1 - 50 out of 60 1 2 >
Match Document Document Title
7446879 Solid-state gyrolaser stabilised by acousto-optic devices  
The field of the invention is that of solid-state laser gyros. One of the major problems inherent in this technology is that the optical cavity of this type of laser gyro is by nature highly...
7388670 LASER gyro readout signal stabilization in high vibration environments  
A method of stabilizing beam power in a ring LASER gyroscope (RKG) during high vibration is provided. The method comprises modifying an electrical signal output from an RLG photodetector to...
6683692 Dither system for motion sensors  
A ring laser gyroscope or other motion sensor is dithered at a first rate if a global positioning signal is available and/or when alignment is not being performed, and is dithered at a second rate...
6603558 Micro-ring cavity gyroscope with magnetic field lock-in minimization  
The invention is a compact optical gyroscope based on the Sagnac effect that combines a micro-ring cavity laser comprising a magneto-optical material and a magnetic field to circumvent the lock-in...
6476918 Dither control system for a ring laser gyro  
A dither control system for a laser gyro having a dither motor for dithering the laser gyro through a desired angular displacement, known as the command angle, in response to a drive signal. In...
6351311 Ring laser gyro with an injected third beam  
A gyro includes a laser device for generating a first and second laser beams to be propagated circuitally in opposition directions. An electric signal is taken out from the laser device. A third...
5517304 Dither generation for ring laser gyroscopes  
A navigation system comprising an RLG (6), means for inducing an oscillatory phase change in the output of the laser of the RLG which simulates an oscillatory dither whose amplitude is in excess of...
5347359 Apparatus and method for correcting ring laser gyroscope phase angle errors induced by lock-in  
Phase errors that occur when a dithered ring laser gyroscope enters its deadband are measured, and a correction is applied to the output of the ring laser gyroscope to compensate for these phase...
5337141 Method and apparatus for distortion free measurements  
The present invention provides a method and apparatus for removing systematic distortion from measurements of an observable parameter. The method and apparatus of the present invention is...
4846574 Retroreflected antilocking feedback  
A ring laser is provided with at least one retroreflector external to the ring laser closed-loop path for redirecting energy extracted from one of the counterpropagating beams into the opposite...
4807998 Ring laser having amplitude and phase controlled externally injected back scatter  
A portion of each of the pair of counter-propagating laser beams in a ring laser cavity are extracted and redirected back into the cavity with servo controlled phase and amplitude. The phase and...
4740085 Scale factor stability control  
In a ring laser gyroscope the sum and the difference of the two opposed beam intensities is utilized, in a first implementation, to correct gain non-linearity, and in a second implementation, to...
4718766 Stabilized ring laser bias system  
In a ring laser with an intracavity saturable absorber and a birefringent cavity, a bias is established whose frequency is less than the axial mode spacing. Bias drift may be nulled on the basis of...
4710027 Method and apparatus for mechanical dither stabilization of a laser angular sensor  
Three sets of laser angular sensors or masses, corresponding to three angularly disposed sensing planes, are mounted on a common instrument block. A compensating mass, which may be a fourth sensor,...
4695160 Error cancelling bias system  
A laser angular rate sensor with a lock-in error cancelling biasing system is disclosed.
4686683 Laser angular rate sensor with dithered mirrors  
A laser angular rate sensor has four corner mirrors forming a substantially square ring laser to reflect two counterpropagating laser beams around a closed path. Dither vibrators are interconnected...
4653920 Ring laser gyroscopes  
A ring laser gyroscope may be oscillated or dithered about its sensing axis to the known `lock-in` effect. The diether motion can comprise an alternating component plus a random component generated...
4648716 Discriminant apparatus for a ring laser angular rate sensor  
The present invention provides a discriminant signal apparatus for providing a discriminant signal indicative of the lock-in rate. The discriminant signal apparatus of the present invention is...
4641970 Ring laser lock-in correction apparatus  
In the present application, an apparatus is provided for altering a ring laser angular rate sensor in such a way that the phase difference between the propagating waves therein includes lock-in...
4632555 Ring laser gyroscopes  
A ring laser gyroscope has a primary ring 13 including a gas discharge tube 4 enclosing an active lasing medium. The gyroscope has additionally a secondary, passive ring 14 optically coupled to the...
4606637 Dithered ring laser gyroscope with residual lock-in error compensation  
A ring laser gyroscope has noise reduction means which removes or compensates for errors which result when a bias or dither is imparted to the gyroscope in order to reduce or avoid lock-in. In one...
4605307 Apparatus for laser gyro  
The present invention discloses an apparatus for laser gyros capable of determining occurring incremental lock-in error by characterizing behavior of the sensor system before and after passing...
4556319 Sensor of rotational velocity on the basis of a ring laser  
A sensor of rotational velocity on the basis of a ring laser having an external radiation path including one corner mirror of the active resonance space which is transparent to the radiation of the...
4529311 Ring laser gyro system  
A laser gyro system is disclosed wherein the lock-in error associated with the sensor signal deriving phase information of the phase relationship between a pair of lasing beams therein is accounted...
4525843 Ring laser with wavefront conjugating beams  
An improvement for a ring laser gyro employs insertion of a wavefront conjugating coupling element inside a laser cavity to reduce the lock-in threshold and to reduce the imbalance between the...
4425040 Ring laser gyroscope cluster for strapped down navigation  
An inertial measurement unit using body dithered ring laser gyroscopes in which the individual ring laser gyroscopes are firmly attached to a common dithered structure and provisions made to cancel...
4398293 Frequency stabilization for two-mode laser  
Frequency stabilization is disclosed for a two-mode laser, such as a Zeeman aser. The emission frequency of the laser is servo-stabilized to the center of the atomic gain curve to provide a stable...
4271397 Nonreciprocal phase shifter for a ring laser gyro  
In a ring laser gyroscope having a triangular optical resonator with mirrors at its corners, in order to prevent lock-in, a portion of the light from the beams that passes through the mirrors at...
4247831 Ring lasers  
The invention provides a ring laser having one or more parallel-sided prisms, or other refracting device, positioned in the light path of the laser resonant cavity formed by, for example, three...
4222668 Ferrimagnetic Faraday elements for ring lasers  
A ring laser having a Faraday cell for biasing the mode locking region beyond the range of rotation rates of interest. The Faraday element included in the cell is a composite comprising a...
4219275 Ring laser having magnetic isolation of counter-propagating light waves  
A ring laser having a nonreciprocal loss element positioned in the aperture of the optical cavity of the laser. The nonreciprocal loss element is adapted to isolate a pair of plane-polarized...
4017187 Double rotation inertial measurement apparatus  
Apparatus for sensing movement with respect to mutually orthogonal axes includes a plurality of ring laser motion sensors, mounted so as to lie as if in planes which would define contiguous...
3941481 Ring laser having elastic wave bias  
A ring laser having beams traveling in opposite directions and elastic wave biasing means in the form of an element of elasto-optic material through which the beams pass in a common optical path....
3927946 Ring laser frequency biasing mechanism  
A ring laser cavity forming component including a magnetically saturable member for differentially phase shifting the contradirectional waves propagating in the laser cavity, the phase shift being...
3879130 Method and apparatus for the operation of ring laser in a biased mode  
A method and apparatus is disclosed for the operation of a ring laser in a biased mode. Two separate cavity resonances support the simultaneous oscillations of two counter-circulating traveling...
3867034 Laser angular rate sensor biasing apparatus  
Electro-optical apparatus for preventing lock-in in a laser angular rate sensor. A Faraday material is placed between two wave plates, the birefringence of each wave plate varying in response to...
3791738 RING LASER UTILIZING AN OPTICAL RETARDATION PLATE TO PREVENT BEAM LOCKING  
Ring laser beam locking is substantially eliminated by inserting an optical retardation plate into the circulating laser beams. The retardation plate is positioned with its optical axis...
3752586 MINIMIZING FREQUENCY LOCKING IN RING LASER GYROSCOPES  
A ring laser gyroscope utilizes a pair of oppositely rotating beams which are given a difference frequency in accordance with the rotation rate of their optical paths. A plurality of frequency...
3744908 EXTERNALLY BIASED RING LASER  
Apparatus to bias a laser gyroscope in which a linear induction motor is positioned adjacent to one leg of the laser gyroscope so as to generate a moving magnetic field in the laser plasma. Such a...
3721497 RING LASER GYROSCOPE LINEARIZATION SYSTEM  
The invention is directed to a system which operates in combination with a ring laser type gyroscope having an output defined by the equation ψ = Ω 30 Ω L sin (ψ + ε) such that the system...
3715562 COMPUTER FOR USE WITH RING LASER ROTATIONAL RATE SENSORS  
A computer responsive to the pulse sequence output signal of a ring laser rotational rate sensor having contra-rotating beams and biasing means to prevent mode locking. The biasing means...
3714607 ACOUSTO-OPTIC METHOD AND APPARATUS FOR MODE DECOUPLING A RING LASER  
An acousto-optic method and apparatus is disclosed for mode decoupling a ring laser. A pair of acousto-optic filters is disposed in the optical path of the ring laser for collinearly diffracting...
3697181 RING LASER HAVING AMPLITUDE AND PHASE CONTROLLED CROSSED-BEAM ANTI-LOCKING FEEDBACK  
A ring laser provided with at least one mirror external to the ring cavity for reflecting energy from one of the two counterrotating laser beams back into the ring to couple to the other beam. The...
3649931 COMPENSATED FREQUENCY BIASING SYSTEM FOR RING LASER  
A compensated Faraday bias cell system is adapted to shift differentially the respective phases of the contradirectionally flowing light waves propagating in a ring laser cavity. The desired phase...
3647303 RING LASER HAVING MEANS FOR PREVENTING MODE LOCKING  
A ring laser having laser beams traveling in opposite directions and a polarizer for circularly polarizing the beams in the same sense to reduce beam coupling within the lasing medium and for...
3646468 SERVO AIDED INJECTION PHASE-LOCKED LASER OSCILLATOR  
A high-power laser oscillator is overcoupled, thereby to be oscillating at below maximum output power, and laser radiation injected into the high-power oscillator from a low-power, controlled...
3627425 LASER GYROSCOPE BIASING APPARATUS  
Electronic apparatus processes the output of a laser gyroscope which is operated with a large amplitude oscillatory bias, to obtain the output after an integer number of bias cycles.
3627422 MEANS FOR AVOIDING LOCKING IN RING LASERS  
Means are disclosed for frequency modulating opposing modes in a ring laser assembly whereby locking is minimized or eliminated. The use of three types of modulators comprising an acoustic...
3575667 SINGLE MODE RING LASER  
A highly mode-selective ring laser is made with primary and auxiliary ring resonators that are coupled through beam splitters that direct out of the laser a large portion of radiation in modes that...
3528029 RING LASER HAVING SYNCHRONIZED PHASE MODULATORS FOR INHIBITING MODE PULLING  
Matches 1 - 50 out of 60 1 2 >