公开(公告)号：CA2117416A1

公开(公告)日：1996-01-26

申请号：CA2117416

申请日：1994-07-25

Applicant: LITTON SYSTEMS INC

Inventor： CORDOVA AMADO ,  BILINSKI DONALD J ,  FERSHT SAMUEL N ,  SURABIAN GLENN M ,  WILDE JOHN D ,  HINMAN PAUL A

IPC: G01C19/72

Abstract: A sensor coil for a fiber optic gyroscope. The coil is formed on a spool of carbon composite material or of another material whose coefficient of thermal expansion approximates that of the overlying windings of the glass optical fiber. The windings are potted in an adhesive material. Various bias effects are addressed by the coil design. The close matching of the thermal expansion characteristics of the spool and the fiber windings as well as proper selection of the coil potting material minimizes the Shupe-like bias caused by thermal stress that would be otherwise exerted by a standard metallic spool. By careful selection of potting material (particularly its modulus of elasticity) vibration-induced bias, coil cracking, degradation of h-parameter and temperature-ramp bias sensitivity are also minimized.

公开(公告)号：DE69826788T2

公开(公告)日：2006-02-09

申请号：DE69826788

申请日：1998-06-25

Applicant: LITTON SYSTEMS INC

Inventor： STEELE JAMES R ,  CORDOVA AMADO ,  GOLDNER ERIC LEE

IPC: G01C19/72 ,  H01S3/06

Abstract: A fiber optic rotation sensor system having improved scale factor stability includes an optically pumped gain fiber arranged to provide optical signals to an integrated optics chip connected to a fiber optic sensing coil. An optical coupler receives optical signals from the gain fiber and provides the optical signals to an optical fiber. The optical fiber is arranged to guide optical signals from the optical coupler along an optical path toward the integrated optics chip such that optical signals from the gain fiber are input to the fiber optic sensing coil to form counter-propagating waves therein. The counter-propagating waves traverse the sensing coil and then combine in the integrated optics chip to form a gyro output signal. A depolarizer is placed in the optical path between the first optical coupler and the integrated optics chip to prevent random changes in the state of polarization of optical signals propagating between the gain fiber and the integrated optic chip.

公开(公告)号：DE69827065T2

公开(公告)日：2005-10-13

申请号：DE69827065

申请日：1998-04-23

Applicant: LITTON SYSTEMS INC

Inventor： CORDOVA AMADO

IPC: G01C19/72

公开(公告)号：DE69827065D1

公开(公告)日：2004-11-25

申请号：DE69827065

申请日：1998-04-23

Applicant: LITTON SYSTEMS INC

Inventor： CORDOVA AMADO

IPC: G01C19/72

公开(公告)号：DE69723409T2

公开(公告)日：2004-06-09

申请号：DE69723409

申请日：1997-10-02

Applicant: LITTON SYSTEMS INC

Inventor： CORDOVA AMADO ,  FERSHT SAMUEL N

IPC: G01C19/72 ,  G02B6/44

Abstract: A fibre optic gyroscope has a sensor coil (18). At least one dummy layer (24) forms an integral structure with, and shares the thermal expansion characteristics of, a potted coil (18) comprising a plurality of layers of windings of a first optical fibre. In the gyroscope, the potted coil (18) is arranged to receive the output of a source of optical energy (10) as a pair of beams that counter-propagate therein and to provide the resultant interference pattern, as gyro output, to a detector (16). The dummy layer (24) displaces layers or windings of the potted coil from regions likely to contribute to Shupe bias effects.

公开(公告)号：CA2240086C

公开(公告)日：2001-09-11

申请号：CA2240086

申请日：1998-06-08

Applicant: LITTON SYSTEMS INC

Inventor： CORDOVA AMADO ,  STEELE JAMES R ,  GOLDNER ERIC LEE

IPC: G01C19/72

Abstract: A fiber optic rotation sensor system having improved scale factor stability includes an optically pumped gain fiber arranged to provide optica l signals to an integrated optics chip connected to a fiber optic sensing coil . An optical coupler receives optical signals from the gain fiber and provides th e optical signals to an optical fiber. The optical fiber is arranged to guide optical signals from the optical coupler along an optical path toward the integrated optics chip such that optical signals from the gain fiber are input to the f iber optic sensing coil to form counter-propagating waves therein. The counter-pr opagating waves traverse the sensing coil and then combine in the integrated optics chip to form a gyro output signal. A depolarizer is placed in the optical path between the first optical coupler and the integrated optics chip to prevent random changes in the state of polarization of optical signa ls propagating between the gain fiber and the integrated optic chip.

公开(公告)号：AU5592498A

公开(公告)日：1999-06-15

申请号：AU5592498

申请日：1997-11-26

Applicant: LITTON SYSTEMS INC

Inventor： CORDOVA AMADO

IPC: G01C19/22 ,  G02B6/16

公开(公告)号：CA2235896A1

公开(公告)日：1998-11-12

申请号：CA2235896

申请日：1998-04-27

Applicant: LITTON SYSTEMS INC

Inventor： CORDOVA AMADO ,  STEELE JAMES R ,  GOLDNER ERIC L ,  HIGBEE JOHN E ,  AUERBACH DANIEL E ,  WONG KA KHA

IPC: G01P9/00 ,  G01C19/72

Abstract: An interferometric rotation rate sensor is arranged to overcome effects of the unavoidable generation of intensity spikes in the modulated optical output. An electrooptical device is located within the optical path of the sensor for receiving the optical output signal from the sensor coil and transforming it prior to application to the photodetector. The electrooptical device is driven by a periodic electrical signal with a period equal to the loop transit time of light traveling through the sensor coil. By synchronizing the periods of attenuation with the predictable presence of spikes in the optical output, valid optical signal information is preserved while gyro electronics are sheltered from the results of optical intensity spiking.

公开(公告)号：CA2232630A1

公开(公告)日：1998-02-05

申请号：CA2232630

申请日：1997-06-26

Applicant: LITTON SYSTEMS INC

Inventor： CORDOVA AMADO ,  GOLDNER ERIC L ,  MARK JOHN G ,  CHERBETTCHIAN AGOP H ,  TAZARTES DANIEL A

IPC: G01C19/72 ,  G01C19/64

Abstract: A gyroscope assembly (10) includes a ring-shaped fiber optic coil (14) and a coil conforming enclosure (12, 16) of high magnetic permeability ferromagnetic material. The enclosure is ring-shaped to conform with the shape of the coil, and includes a portion (22) extending within the internal hole of the coil ring. Therefore, the coil is intimately and fully encased within high magnetic permeability material. In particular, the enclosure comprises a coil supporting spool (12) and a cover (16) secured to the spool. The spool includes a base (18) which is provided with a central hole (20) and a tubular wall (22) extending perpendicularly from the base. Coil (14) is bonded to base (18). Both the spool and the cover are formed of high magnetic permeability material, and the cover is placed about the fiber optic coil and attached to the spool. The coefficient of thermal expansion material used for the spool is matched to that of the coil pack to minimize stress imposed upon the fiber. An outer shield (28), roughly cylindrical in shape, may be further attached to the outside of the inner, toroidal shield, and the two shields are separated by a layer of low magnetic permeability material, such as of low magnetic permeability stainless steel or aluminum.