Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
  • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
  • G01S7/481—Constructional features, e.g. arrangements of optical elements
  • G01S7/4818—Constructional features, e.g. arrangements of optical elements using optical fibres
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P3/00—Measuring linear or angular speed; Measuring differences of linear or angular speeds
  • G01P3/64—Devices characterised by the determination of the time taken to traverse a fixed distance
  • G01P3/68—Devices characterised by the determination of the time taken to traverse a fixed distance using optical means, i.e. using infrared, visible, or ultraviolet light
  • G01P3/685—Devices characterised by the determination of the time taken to traverse a fixed distance using optical means, i.e. using infrared, visible, or ultraviolet light for projectile velocity measurements
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
  • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
  • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
  • G01S17/50—Systems of measurement based on relative movement of target
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4219—Mechanical fixtures for holding or positioning the elements relative to each other in the couplings; Alignment methods for the elements, e.g. measuring or observing methods especially used therefor
  • G02B6/422—Active alignment, i.e. moving the elements in response to the detected degree of coupling or position of the elements
  • G02B6/4226—Positioning means for moving the elements into alignment, e.g. alignment screws, deformation of the mount
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4296—Coupling light guides with opto-electronic elements coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources

Definitions

• the present invention relates to a device for injecting a laser beam into the end of an optical fiber and for recovering the light coming from this end of the optical fiber, this device comprising:
• these reflection means comprising a hole which allows the passage of the laser beam.
• the present invention applies in particular to any measurement system which requires the injection of a laser beam into the end of an optical fiber and the recovery, for further processing, of the light which comes from this end of the optical fiber and which results from an interaction of the laser beam with an object on the side of the other end of this optical fiber.
• the invention applies in particular to equipment for measuring the speed of a projectile by interferometry.
• a laser beam passes through a pierced mirror and, via an optic, is injected into the end of an optical fiber.
• this laser beam is reflected or scattered by a projectile and the reflected or scattered light is transmitted by the optical fiber, comes out of the latter and undergoes an appropriate treatment after reflection on the mirror.
• the present invention overcomes these drawbacks.
• the invention solves the problem of obtaining a compact and adjustable device in a short time, making it possible to optimally inject, by means of light reflection, a laser beam into an optical fiber, to recover the light from this optical fiber and reflect this Light on the means of reflection.
• the injection and recovery device which is the subject of the present invention is characterized in that it comprises, in addition to its focusing optics and means for reflecting light:
• this device also comprises:
• first translation-rotation means comprise:
• the device which is the subject of the invention further comprises a fifth support on which is mounted the second support and the second translation-rotation means comprise: translation means, along fifth and sixth axes perpendicular to each other, and of rotation, around a seventh axis perpendicular to these fifth and sixth axes and to the fourth axis, of the fifth support with respect to the first support, and
• the seventh axis and the ninth axis meet at a point which belongs to the axis of said end of the optical fiber.
• the device which is the subject of the invention can also comprise:
• a sixth support which is mounted on the first support and on which are mounted the reflection means, and.
• the device which is the subject of the invention can also further comprise:
• FIG. 1 is a schematic view of a speed measuring equipment comprising a device according to the invention
• Figure 2 is a perspective view of a particular embodiment of the device object of the invention
• Figure 3 is a partially sectioned top view of the device shown in Figure 2
• Figures 4A and 4B i They illustrate diagrammatically two possible embodiments of the present invention.
• the installation shown diagrammatically in FIG. 1 makes it possible to measure the speed of a projectile by interferometry.
• This installation includes:
• the focusing head 6 comprises:
• the head 6 is made rigidly integral with a projecti the 14 intended to be projected in the direction of this head 6 by a thruster not shown.
• the projecti on 14 is placed opposite the Lens 12.
• the focusing head 6 further comprises a section of multimode optical fiber 16, mounted on the support 10 along the axis of the lens 12 and located opposite the projectile 14 relative to this lens 12.
• That of the ends of the section 16 which is not directly opposite the lens 12 is provided with an optical connector 18 and optically connected to the optical fiber FO by means of this connector.
• the installation schematically shown in FIG. 1 also includes a device 20 according to the invention and designed to inject the beam from the Laser 2 into one end of the optical fiber FO.
• the laser beam which is thus transmitted by this optical fiber FO, is sent, via the optical fiber section 16 and the lens 12, on the projectile 14 which is optically reflective or diffuse.
• the light reflected or scattered by this projectile 14 is partially recovered by the optical fiber F0 thanks to the lens 12 and returns to the device according to the invention 20 which is also provided for recovering this light and forming from the latter a beam output light 22.
• This output light beam 22 is sent to the interferometric measurement means 8 by means of an auxiliary mirror 24.
• interferometric measurement means 8 comprise: a Perot-Fabry interferometer 26,
• a materialization means 30 which can be an analysis slot or a flat fluorescent screen, placed after the lens 28, and an optoelectronic scanning camera 32 which is arranged following the materialization means 30 and which is designed to capture with its input objective, the light traces formed in the plane of the materialization means 30.
• the camera 32 is connected to means 34 for processing and possibly viewing, electrical or optical signals which it is capable of supplying. Also seen in Figure 1 a clear blade 36 which is arranged at the output of the laser 2 and intended to send, on a screen 38, part of the light recovered by the injection and recovery device according to the invention 20. Between the laser 2 and this device 20, the optical path can be arbitrary and can, in particular, include mirrors and lenses (not shown) provided that the light beam which enters the injection and recovery device 20, has characteristics of diameter and divergence compatible with this device 20.
• the core of the optical fiber F0 used in the installation which is shown in FIG. 1 is worth 0.2 mm and this optical fiber FO is terminated, at its end which is intended to be optically connected to device 20, by a ferrule or ferrule, or by an optical plug, compatible with this device 20.
• the particular embodiment of the device object of the invention which is shown in perspective in FIG. 2 and partially seen from above cut in Figure 3, includes, as seen in these Figures 2 and 3: - a first support S1 which has three plates s1a, s1b and sic rigidly secured to one another and perpendicular to each other. The support S1 being therefore called thereafter "trihedron S1",
• a third support S3 comprising two plates s3a and s3b rigidly secured to one another and perpendicular to each other, this support S3 being therefore called subsequently "bracket S3",
• optical fiber block S5 a fifth support S5 on which the optical fiber holder S2 is mounted and which is hereinafter called “optical fiber block S5", and
• a sixth support S6 which carries an OS output objective, this OS objective having an axis Y along which propagates the output beam supplied by the device shown in FIGS. 2 and 3.
• This device shown in Figures 2 and 3 also includes:
• a mirror M which is mounted on the support S6 and inclined at 45 ° on an axis Z which constitutes the axis of the device shown in Figures 2 and 3, the X axis of the incident laser beam and the axis of the end of the optical fiber FO being coincident with the axis Z when the device is properly adjusted and this axis Z also being the axis of a hole T that comprises the mirror H, and - an injection lens LU intended to focus the incident laser beam on the end of the optical fiber FO, through the hole T of the mirror M.
• the light which comes from this end of the optical fiber FO is reflected by the mirror M towards the objective OS whose axis Y is perpendicular to the axis Z.
• the lens LU is mounted at the end of an externally threaded lens cylinder PLU, which is screwed into an injection sleeve FI provided with a locating lock nut CE1.
• the OS output lens is located in an externally threaded KOS mount.
• This MOS mount is screwed into a FOS sleeve that includes the support 56 and which is provided with a CE2 locking lock nut.
• the injection lens LU is a plano-convex lens whose focal distance is equal to 50 millimeters or 80 mm and which is treated with anti-reflex,
• the mirror M is a plane mirror whose face which is opposite the optical fiber holder S2 is reflecting, the hole T being at 45 ° from the normal to this reflecting face, and
• the OS output lens is a lens whose focal length is equal to 120mm, whose aperture is equal to half of this focal length and which combines the focal plane with infinity.
• the S2 optical fiber holder which is designed to receive an end cap, could be replaced by another optical fiber holder designed to receive an optical plug of the kind of those sold by the company RADIALL in the OptabalL series.
• the device shown in FIGS. 2 and 3 can be provided, as seen in FIG. 3, with a removable adjustment pattern MR intended for the orientation of this device When it is mounted on the latter.
• the MR test pattern makes it possible to adjust this device with respect to the incident laser beam so that this beam returns to the laser.
• the MR target is constituted by a circular plane mirror carrying, engraved in its center, a circle.
• this circle has a diameter of two millimeters while the diameter of the circular plane mirror is 30 mm.
• This circular plane mirror is extended by a rod whose axis coincides with the axis of this circular plane mirror and which slides into the PLU injection lens holder, the circular plane mirror being strictly perpendicular to the axis. Z of the device.
• the bracket S3 is mounted on the base S4 by means of a movement M1 and a movement M2.
• the base S4 carries the movement M1 which is a translational movement along an axis X1 parallel to the plane of the base S4.
• This movement M1 carries the movement M2 which is a rotational movement around an axis X2 perpendicular to the plane of the base S4.
• the S3 bracket is mounted on the M2 movement.
• the movement M1 is therefore a movement of horizontal translation and the movement M2 a movement of rotat on about a vertical axis.
• the trihedron S1 is mounted on the square S3 through an M3 movement and an M4 movement.
• the movement M3, which is integral with the bracket S3, is a translational movement along an axis X3 parallel to the axis X2.
• the movement M4, which is mounted on the movement M3, is a rotational movement around an axis X4 parallel to the plane of the base S4.
• the trihedron S1 is mounted on this movement M4 in the manner shown in FIG. 2.
• the movement M3 is a movement of vertical translation and the movement M4 is a movement of rotation about a horizontal axis.
• the optical fiber block S5 is mounted on the trihedron S1 in the manner indicated in FIG. 2, by means of movements M5, M6 and M7.
• the movement M5 which is integral with the trihedron if, is a translational movement along an axis X5 parallel to the X4 axis.
• the movement M6, which is mounted on the movement M5, is a translational movement along an axis X6 which is perpendicular to the axis X5 and parallel to the axis Z of the device.
• the movement M7 which is mounted on the movement M6 and which carries the fiber optic unit £ 5, is a rotational movement around an axis X7 which is perpendicular to the axis X5 and to the axis X6.
• the optical fiber holder S2 is mounted on the optical fiber bLoc S5 in the manner indicated in FIG. 2, by means of movements M8 and M9.
• the movement M8, which is integral with the optical fiber block S5, is a translational movement along an axis X8 parallel to the axis X7.
• the movement M9 which is mounted on the movement M8, is a rotational movement around an axis X9 perpendicular to the axis X8.
• This movement M9 supports the optical fiber holder S2.
• the support S6 is mounted on the trihedron S1, opposite the optical fiber block S5 and by means of a movement H10.
• This movement M10 is a rotary movement around the axis Z of the device shown in FIGS. 2 and 3.
• this OS output optic By screwing or unscrewing the MOS mount of the OS output optic, this OS output optic is moved in translation along the Y axis of this OS optic, this Y axis being perpendicular to the Z axis of the device represented on the Figures 2 and 3.
• the rotational movement M10 makes it possible to rotate the OS optics and therefore the Y axis around the Z axis between a first position where this Y axis is parallel to the X5 axis and a position where this Y axis makes an angle. 85 ° with this axis X5.
• the axis of rotation X9 is contained in the plane of the internal face Fint of the optical fiber holder S2, this internal face being opposite the mirror M.
• the axes of rotation X7 and X9 are perpendicular to each other and meet at a point which is on this internal face Fint.
• the axis Z of the device shown in Figures 2 and 3 is perpendicular to the axes X7 and X9 and passes through this point.
• the end face of the optical fiber FO is in the plane of this internal face Fint.
• the axis of the end of the optical fiber FO and the axes X7 and X9 form a trirectangle trihedron whose apex is on the internal face Fint of the door - S2 optical fiber.
• the axis Z of the device is approximately parallel to this axis X of the incident laser beam.
• the pale spots surrounding these two light points being the images of the end face of the optical fiber or more exactly of the heart of this optical fiber, center these pale spots around the corresponding light points by means of the movements M5 and M8.
• This device shown in FIGS. 2 and 3 includes all the elements allowing:
• This straight version is schematically represented in FIG. 4A in top view.
• the half-plane in question is located to the left of the corresponding device, when looking in the opposite direction of the incident laser beam.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Optics & Photonics (AREA)
• Computer Networks & Wireless Communication (AREA)
• Radar, Positioning & Navigation (AREA)
• Remote Sensing (AREA)
• Electromagnetism (AREA)
• Optical Couplings Of Light Guides (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9410533

Family Applications (1)

Country Status (3)

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Family Cites Families (4)

• 1991
  • 1991-03-08 FR FR9102834A patent/FR2673729B1/fr not_active Expired - Fee Related
• 1992
  • 1992-03-06 WO PCT/FR1992/000209 patent/WO1992015910A1/fr not_active Application Discontinuation
  • 1992-03-06 EP EP19920907281 patent/EP0574499A1/de not_active Withdrawn

Non-Patent Citations (1)

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