公开(公告)号：JP2000036630A

公开(公告)日：2000-02-02

申请号：JP18806699

申请日：1999-05-28

Applicant: LITTON SYSTEMS INC

Inventor： ROZELLE DAVID M ,  MICHAL RONALD J ,  LAM LEO K ,  CAPPI JOHN F

IPC: H01S3/094 ,  G01C19/72 ,  H01S3/06 ,  H01S3/067

Abstract: PROBLEM TO BE SOLVED: To eliminate the backward reflection of exciting light by providing a stimulation light source which gives stimulation light to an optical fiber and guides the light to a first light shutter. SOLUTION: An optical light source is constituted in such a way that the light outputted from a first light shutter 18 is inputted to a wavelength multiplexer 26 and a gain fiber 34 is connected to the multiplexer 26 so that the wide-band light which is optically stimulated by stimulation light and outputted may be propagated to the multiplexer. In addition, an output optical fiber 29 is also connected to the multiplexer 26 so that part of the wide-band light sent from the gain fiber 34 may be guided to a second light shutter 50 and inputted to a fiber optic rotation sensor.

公开(公告)号：JPH1030955A

公开(公告)日：1998-02-03

申请号：JP4908497

申请日：1997-03-04

Applicant: LITTON SYSTEMS INC

Inventor： FREDERICK DONALD A ,  CAPPI JOHN F

IPC: G01B9/02 ,  G01H9/00 ,  G01V1/18 ,  G02B6/36 ,  H04B13/00 ,  H04R1/44 ,  H04R23/00

Abstract: PROBLEM TO BE SOLVED: To achieve the cost reduction of a hydrophone device, the simplification of part designs and reliability by forming a sensing arm as a coil, and incorporating an optical fiber having a certain length, which is arranged so that the change in optical-path length is experienced when an optical-fiber hydrophone is exposed to a sound field. SOLUTION: A reference arm 26 of an optical-fiber interferometer undergoes direct wet winding on a rod 32 formed of rigid material such as metal. Then, the elastic layer comprising potting material 40 and material such as urethane is formed on the reference arm 26. Then, a sensing arm 24 is wound on the elastic layer and covered with an elastic layer 44. In this way, a mandrel 30, to which the sensing arm 24 and the reference arm 26 are attached, is stable because the length of the reference arm 26 is wound on the rigid rod 32 when the mandrel is immersed in water and affected by a sound field. The change in sound field causes the change in length of the sensing arm 24, changes the optical-path length of the sensing arm 24 and generates the optical signal, which is processed so as to measure the change in intensity of the sound field.

公开(公告)号：DE69721869T2

公开(公告)日：2004-02-19

申请号：DE69721869

申请日：1997-02-25

Applicant: LITTON SYSTEMS INC

Inventor： FREDERICK DONALD A ,  CAPPI JOHN F

IPC: G01B9/02 ,  G01H9/00 ,  G01V1/18 ,  G02B6/36 ,  H04B13/00 ,  H04R1/44 ,  H04R23/00

Abstract: A hydrophone has a fibre optic interferometer with a reference arm (26) formed by a length of optical fibre wound around a rigid mandrel (30) and with constant optical path length, elastic material (42) over the arm, and a concentric sensing arm (24) with a length of optical fibre wound over the material in a coil so that optical path length changes when the hydrophone is exposed to an acoustic field. Optical output signals are passed to a processor to measure acoustic pressure. Preferably, the elastic material is preferably polyurethane, and the sensing arm is encased in further elastic material (44) and spaced from the reference arm. The mandrel is e.g. a solid rod of metal or other rigid material with end flanges, and the reference arm is potted.

公开(公告)号：CA2199087C

公开(公告)日：2001-02-20

申请号：CA2199087

申请日：1997-03-04

Applicant: LITTON SYSTEMS INC

Inventor： FREDERICK DONALD A ,  CAPPI JOHN F

IPC: G01B9/02 ,  G01H9/00 ,  G01V1/18 ,  G02B6/36 ,  H04B13/00 ,  H04R1/44 ,  H04R23/00 ,  H04B10/12

Abstract: A fiber optic interferometric sensor for use in a hydrophone system at high pressures includes a reference fiber wrapped around a rigid inner cylinder. A solid layer of compliant material is applied over the reference fiber. The sensing arm of the interferometer is wound over the layer of material applied over the reference fiber. The outer material is sufficiently compliant to provide acoustic sensitivity comparable to that of air-backed hydrophones.

公开(公告)号：AU1512197A

公开(公告)日：1997-09-11

申请号：AU1512197

申请日：1997-03-05

Applicant: LITTON SYSTEMS INC

Inventor： FREDERICK DONALD A ,  CAPPI JOHN F

IPC: G01B9/02 ,  G01H9/00 ,  G01V1/18 ,  G02B6/36 ,  H04B13/00 ,  H04R1/44 ,  H04R23/00 ,  G01L11/02 ,  G01B11/22

Abstract: A hydrophone has a fibre optic interferometer with a reference arm (26) formed by a length of optical fibre wound around a rigid mandrel (30) and with constant optical path length, elastic material (42) over the arm, and a concentric sensing arm (24) with a length of optical fibre wound over the material in a coil so that optical path length changes when the hydrophone is exposed to an acoustic field. Optical output signals are passed to a processor to measure acoustic pressure. Preferably, the elastic material is preferably polyurethane, and the sensing arm is encased in further elastic material (44) and spaced from the reference arm. The mandrel is e.g. a solid rod of metal or other rigid material with end flanges, and the reference arm is potted.

公开(公告)号：NO971036D0

公开(公告)日：1997-03-06

申请号：NO971036

申请日：1997-03-06

Applicant: LITTON SYSTEMS INC

Inventor： FREDERICK DONALD A ,  CAPPI JOHN F

IPC: G01H9/00 ,  G01V1/18 ,  G01B9/02 ,  G02B6/36 ,  H04B13/00 ,  H04R1/44 ,  H04R23/00

Abstract: A hydrophone has a fibre optic interferometer with a reference arm (26) formed by a length of optical fibre wound around a rigid mandrel (30) and with constant optical path length, elastic material (42) over the arm, and a concentric sensing arm (24) with a length of optical fibre wound over the material in a coil so that optical path length changes when the hydrophone is exposed to an acoustic field. Optical output signals are passed to a processor to measure acoustic pressure. Preferably, the elastic material is preferably polyurethane, and the sensing arm is encased in further elastic material (44) and spaced from the reference arm. The mandrel is e.g. a solid rod of metal or other rigid material with end flanges, and the reference arm is potted.

公开(公告)号：NO322785B1

公开(公告)日：2006-12-11

申请号：NO971036

申请日：1997-03-06

Applicant: LITTON SYSTEMS INC

Inventor： FREDERICK DONALD A ,  CAPPI JOHN F

IPC: G01B9/02 ,  G01H3/00 ,  G01H9/00 ,  G01V1/18 ,  G02B6/36 ,  H04B13/00 ,  H04R1/44 ,  H04R23/00

Abstract: A hydrophone has a fibre optic interferometer with a reference arm (26) formed by a length of optical fibre wound around a rigid mandrel (30) and with constant optical path length, elastic material (42) over the arm, and a concentric sensing arm (24) with a length of optical fibre wound over the material in a coil so that optical path length changes when the hydrophone is exposed to an acoustic field. Optical output signals are passed to a processor to measure acoustic pressure. Preferably, the elastic material is preferably polyurethane, and the sensing arm is encased in further elastic material (44) and spaced from the reference arm. The mandrel is e.g. a solid rod of metal or other rigid material with end flanges, and the reference arm is potted.

公开(公告)号：DE69721869D1

公开(公告)日：2003-06-18

申请号：DE69721869

申请日：1997-02-25

Applicant: LITTON SYSTEMS INC

Inventor： FREDERICK DONALD A ,  CAPPI JOHN F

IPC: G01B9/02 ,  G01H9/00 ,  G01V1/18 ,  G02B6/36 ,  H04B13/00 ,  H04R1/44 ,  H04R23/00

Abstract: A hydrophone has a fibre optic interferometer with a reference arm (26) formed by a length of optical fibre wound around a rigid mandrel (30) and with constant optical path length, elastic material (42) over the arm, and a concentric sensing arm (24) with a length of optical fibre wound over the material in a coil so that optical path length changes when the hydrophone is exposed to an acoustic field. Optical output signals are passed to a processor to measure acoustic pressure. Preferably, the elastic material is preferably polyurethane, and the sensing arm is encased in further elastic material (44) and spaced from the reference arm. The mandrel is e.g. a solid rod of metal or other rigid material with end flanges, and the reference arm is potted.

公开(公告)号：AU720000B2

公开(公告)日：2000-05-18

申请号：AU1512197

申请日：1997-03-05

Applicant: LITTON SYSTEMS INC

Inventor： FREDERICK DONALD A ,  CAPPI JOHN F

IPC: G01B9/02 ,  G01H9/00 ,  G01V1/18 ,  G02B6/36 ,  H04B13/00 ,  H04R1/44 ,  H04R23/00 ,  G01L11/02 ,  G01B11/22

Abstract: A hydrophone has a fibre optic interferometer with a reference arm (26) formed by a length of optical fibre wound around a rigid mandrel (30) and with constant optical path length, elastic material (42) over the arm, and a concentric sensing arm (24) with a length of optical fibre wound over the material in a coil so that optical path length changes when the hydrophone is exposed to an acoustic field. Optical output signals are passed to a processor to measure acoustic pressure. Preferably, the elastic material is preferably polyurethane, and the sensing arm is encased in further elastic material (44) and spaced from the reference arm. The mandrel is e.g. a solid rod of metal or other rigid material with end flanges, and the reference arm is potted.

公开(公告)号：CA2199087A1

公开(公告)日：1997-09-06

申请号：CA2199087

申请日：1997-03-04

Applicant: LITTON SYSTEMS INC

Inventor： CAPPI JOHN F ,  FREDERICK DONALD A

IPC: G01B9/02 ,  G01H9/00 ,  G01V1/18 ,  G02B6/36 ,  H04B13/00 ,  H04R1/44 ,  H04R23/00 ,  H04B10/12

Abstract: A fiber optic interferometric sensor for use in a hydrophone system at high pressures includes a reference fiber wrapped around a rigid inner cylinder. A solid layer of compliant material is applied over the reference fiber. The sensing arm of the interferometer is wound over the layer of material applied over the referenc e fiber. The outer material is sufficiently compliant to provide acoustic sensitivity com parable to that of air-backed hydrophones.