-
公开(公告)号：US6434283B2
公开(公告)日：2002-08-13
申请号：US51492200
申请日：2000-02-28
Applicant: LITTON SYSTEMS INC
Inventor： FREDERICK DONALD ADAM , HALL DAVID BARNETT
Abstract: A fiber-optic acoustical sensor system includes a light source, an elongate optical cable conducting light from the light source to an optical acoustical transducer located at a distance from the light source along this cable, and a polarizer at the acoustical transducer. The sensor system includes a polarizer providing orthogonally-polarized light along the optical cable to the polarizer located adjacent to the transducer. Because of the polarizer adjacent to the transducer, disturbances of the optical cable and resulting polarization perturbations of the light transmitted along this cable do not affect the optical acoustical transducer. The acoustic transducer is responsive to sound energy to provide an optical return signal indicative of this sound energy. An in-line fiber-optic polarizer suitable for use in this acoustical transducer includes a pair of confronting optical fiber portions aligned along an optical axis and which each define end surfaces disposed at a Brewster polarizer angle with respect to light transmitted along this optical axis. The end surface of one of these optical fibers carries plural alternating sub-layers of high-index and low-index dielectric material, which are effective to p-polarize the transmitted light and substantially eliminate s-polarized light transmission to the optical acoustical transducer.
Abstract translation: 光纤声学传感器系统包括光源，细长的光缆，其将来自光源的光传导到沿着该电缆位于距离光源一定距离处的光声换能器，以及在声换能器处的偏振器。 传感器系统包括偏振器，其沿着光缆向邻近换能器的偏振器提供正交偏振光。 由于靠近传感器的偏振器，光缆的干扰和沿着该电缆传输的光的偏振扰动不影响光学声学传感器。 声换能器响应于声能以提供指示该声能的光返回信号。 适用于这种声学换能器的直列式光纤偏振器包括沿光轴对准的一对相对的光纤部分，并且每对光纤部分限定相对于沿该光轴传输的光布置在布鲁斯特偏振镜角度的端面。 这些光纤中的一个的端面承载了高折射率和低折射率介电材料的多个交替子层，其有效地对透射光进行p偏振，并且基本上消除了对光学换能器的s偏振光透射。
-
公开(公告)号：CA2315591C
公开(公告)日：2003-06-24
申请号：CA2315591
申请日：2000-07-24
Applicant: LITTON SYSTEMS INC
Inventor： HALL DAVID BARNETT
Abstract: A sinusoidal phase generated carrier is used to demodulate signal outpu t from an interferometric sensor array. Optical signals input to the array are modulated with a sinusoid. Output signals are sampled and integrated over portions of a period of the phase generated carrier. A key to this method of sampling is the existence of pairs of signals associated with integration over two 180.degre e. out-of-phase portions of the phase generated carrier. This invention is a four step metho d involves the implementation of two pairs of such signals to determine the phase shift in each sensor in the array.
-
公开(公告)号：FR2729753B1
公开(公告)日：1997-08-14
申请号：FR9001505
申请日：1990-02-09
Applicant: LITTON SYSTEMS INC
Inventor： HALL DAVID BARNETT , LAM LEO K
IPC: G01C19/66
Abstract: Disclosed herein is a multi-pole magnetic geometry for a multi-oscillator ring laser gyroscope. Multi-pole magnetic geometry configurations are disclosed which are useful for providing Faraday rotation where the multi-oscillator uses a Faraday rotator and high magnetic field effect where the nature of the multi-oscillator ring laser gyroscope is of split gain configuration. The multi-post magnetic geometry includes a plurality of top or bottom loaded diametrically opposed north and south pole axially directed magnets which are positioned substantially transverse to the optical pathway but suitable for providing axially directed magnetic fields to portions of the optical pathway only where desired. The multi-pole magnetic geometry disclosed herein substantially produces a magnetic flux that is restricted in its position to localized portions of the optical pathway with low far field effects.
-
公开(公告)号：NO20003819A
公开(公告)日：2000-10-04
申请号：NO20003819
申请日：2000-07-25
Applicant: LITTON SYSTEMS INC
Inventor： HALL DAVID BARNETT , BUNN JR JAMES SYLVESTER
CPC classification number: G01D5/35303 , G01D5/35383
-
公开(公告)号：NO20003819D0
公开(公告)日：2000-07-25
申请号：NO20003819
申请日：2000-07-25
Applicant: LITTON SYSTEMS INC
Inventor： HALL DAVID BARNETT , BUNN JR JAMES SYLVESTER
Abstract: Leakage optical signals injected into a time division multiplexed sensor system are modulated during off periods in the duty cycle in the sensor interrogation signal. The leakage light is modulated such that its unwanted contributions to the sensor output signals are displaced in frequency from the base band frequency. This frequency displacement greatly reduces unwanted noise power in the received signals.
-
Patent Agency Ranking
公开(公告)号：NO844735A
公开(公告)日：1985-06-20
申请号：NO844735
申请日：1984-11-28
Applicant: LITTON SYSTEMS INC
Inventor： HALL DAVID BARNETT
CPC classification number: G02B6/2852 , G02B6/2826
-
公开(公告)号：CA2315591A1
公开(公告)日：2001-01-30
申请号：CA2315591
申请日：2000-07-24
Applicant: LITTON SYSTEMS INC
Inventor： HALL DAVID BARNETT
Abstract: A sinusoidal phase generated carrier is used to demodulate signal outpu t from an interferometric sensor array. Optical signals input to the array are modulated with a sinusoid. Output signals are sampled and integrated over portions of a period of the phase generated carrier. A key to this method of sampling is the existence of pairs of signals associated with integration over two 180.degre e. out-of-phase portions of the phase generated carrier. This invention is a four step metho d involves the implementation of two pairs of such signals to determine the phase shift in each sensor in the array.
-
公开(公告)号：BR8405445A
公开(公告)日：1985-09-03
申请号：BR8405445
申请日：1984-10-25
Applicant: LITTON SYSTEMS INC
Inventor： HALL DAVID BARNETT
Abstract: This invention is a three port fiber optic coupler for coupling light between a straight fiber having a planar exposed core portion on an end thereof and a curved fiber having an exposed planar portion on the side of the curved fiber. The curved fiber is mounted in an arcuate groove in a flat surface of a substrate which has been ground and polished to expose a portion of the core of the curved fiber. The straight fiber intersects the exposed surface of the core of the curved fiber at a predetermined angle, and the end of the straight fiber is formed such that the exposed core at the end of the straight fiber has an area that matches the area of the exposed core portion of the curved fiber as closely as possible to minimize signal loss in the coupler.
-
公开(公告)号：AU3209084A
公开(公告)日：1985-06-27
申请号：AU3209084
申请日：1984-08-20
Applicant: LITTON SYSTEMS INC
Inventor： HALL DAVID BARNETT
Abstract: This invention is a three port fiber optic coupler for coupling light between a straight fiber having a planar exposed core portion on an end thereof and a curved fiber having an exposed planar portion on the side of the curved fiber. The curved fiber is mounted in an arcuate groove in a flat surface of a substrate which has been ground and polished to expose a portion of the core of the curved fiber. The straight fiber intersects the exposed surface of the core of the curved fiber at a predetermined angle, and the end of the straight fiber is formed such that the exposed core at the end of the straight fiber has an area that matches the area of the exposed core portion of the curved fiber as closely as possible to minimize signal loss in the coupler.
-
公开(公告)号：NO844735L
公开(公告)日：1985-06-20
申请号：NO844735
申请日：1984-11-28
Applicant: LITTON SYSTEMS INC
Inventor： HALL DAVID BARNETT
Abstract: This invention is a three port fiber optic coupler for coupling light between a straight fiber having a planar exposed core portion on an end thereof and a curved fiber having an exposed planar portion on the side of the curved fiber. The curved fiber is mounted in an arcuate groove in a flat surface of a substrate which has been ground and polished to expose a portion of the core of the curved fiber. The straight fiber intersects the exposed surface of the core of the curved fiber at a predetermined angle, and the end of the straight fiber is formed such that the exposed core at the end of the straight fiber has an area that matches the area of the exposed core portion of the curved fiber as closely as possible to minimize signal loss in the coupler.
-
-
-
-
-
-
-
-
-
Search Results
13
records
(took 0.021 seconds)
