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GB1594336A - Opitcal apparatus for switching or variably coupling light between a plurality of optical fibre light guides - Google Patents

Opitcal apparatus for switching or variably coupling light between a plurality of optical fibre light guides Download PDF

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Publication number
GB1594336A
GB1594336A GB5328276A GB5328276A GB1594336A GB 1594336 A GB1594336 A GB 1594336A GB 5328276 A GB5328276 A GB 5328276A GB 5328276 A GB5328276 A GB 5328276A GB 1594336 A GB1594336 A GB 1594336A
Authority
GB
United Kingdom
Prior art keywords
light
optical
devices
optical devices
light guide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB5328276A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Plessey Co Ltd
Original Assignee
Plessey Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Plessey Co Ltd filed Critical Plessey Co Ltd
Priority to GB5328276A priority Critical patent/GB1594336A/en
Publication of GB1594336A publication Critical patent/GB1594336A/en
Expired legal-status Critical Current

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Classifications

    • 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
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/351—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements
    • G02B6/3522—Optical coupling means having switching means involving stationary waveguides with moving interposed optical elements the optical element enabling or impairing total internal reflection
    • 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
    • G02B6/26—Optical coupling means
    • G02B6/28—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals
    • G02B6/2804—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers
    • G02B6/2817—Optical coupling means having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers using reflective elements to split or combine optical signals
    • 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
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/354—Switching arrangements, i.e. number of input/output ports and interconnection types
    • G02B6/3544—2D constellations, i.e. with switching elements and switched beams located in a plane
    • G02B6/3546—NxM switch, i.e. a regular array of switches elements of matrix type constellation
    • 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
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3564—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
    • G02B6/3568—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details characterised by the actuating force
    • G02B6/3572—Magnetic force
    • 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
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3564—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
    • G02B6/3568—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details characterised by the actuating force
    • G02B6/3574—Mechanical force, e.g. pressure variations
    • 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
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3564—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
    • G02B6/3568—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details characterised by the actuating force
    • G02B6/3576—Temperature or heat actuation
    • 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
    • G02B6/26—Optical coupling means
    • G02B6/35—Optical coupling means having switching means
    • G02B6/3564—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details
    • G02B6/3568—Mechanical details of the actuation mechanism associated with the moving element or mounting mechanism details characterised by the actuating force
    • G02B6/3578—Piezoelectric force

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Mechanical Light Control Or Optical Switches (AREA)

Description

(54) OPTICAL APPARATUS FOR SWITCHING OR VARIABLY COUPLING LIGHT BETWEEN A PLURALITY OF OPTICAL FIBRE LIGHT GUIDES (71) We, THE PLESSEY COMPANY LIM- ITED, a British Company, of Vicarage Lane, Ilford, Essex, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to optical apparatus for switching or variably coupling light between a plurality of optical fibre light guides.
The use of optical fibre light guides for conducting light from place to place is well known. There is a need for a simple device which enables the light guides to be switched or variably coupled so that light passing along a light guide can either be switched to another light guide or can be coupled to several light guides with variable degrees of intensity. It is an aim of the present invention to provide such apparatus.
According to the present invention optical apparatus for switching or variably coupling light guides, comprises two optical devices which are relatively movable into and out of contact with each other and a plurality of optical fibre light guides arranged around the two optical devices with their ends spaced from and their axes passing through the two optical devices. the two optical devices being constructed such that when they are in contact. light from any of the light guides continues to pass along its axis straight through the two optical devices. and when the two optical devices are not in contact with each other, light from any of the light guides is at least partially reflected through an angle by one of the optical devices.
Preferably. each optical device is capable of totally internally reflecting light when the two optical devices are not in contact with each other.
The optical devices of the present invention may have various shapes and a presently preferred shape is that of a half cube or prism. The optical devices are such that their adjacent surfaces will normally be planar.
Curved adjacent surfaces may sometimes be employed but then magnification will usually result.
The optical devices may be made of any suitable transparent optical material such, for example, as glass or silica. Transparent plastics materials may also be employed and these will usually be transparent acrylic plastics materials such, for example, as Perspex (Registered Trade Mark).
The optical apparatus of the invention preferably includes means for relatively moving the optical devices into and out of contact with each other. The means for relatively moving the optical devices may be capable of moving them apart by a distance of a quarter of a wavelength or 250nm apart.
Generally, the further that the optical devices are moved apart, then the greater will be the reflection given by the devices. Thus, in switching applications, it will clearly be desirable to have the optical devices movable sufficiently far apart that good internal reflection is achieved. In cases where the optical apparatus of the invention is to be used as a variable coupler, then the optical devices will not be moved so far apart since it may be desirable to couple the light from one light guide into two or more other light guides. In this case, the original intensity of the light will be diminished since the original light beam will be split up. By appropriately controlling the spacing of the optical devices, the intensity of the light directed along the coupled light guides can be controlled.
Preferably, the means for relatively moving the optical devices into and out of contact with each other is a piezoelectric device. If desired however, the means for relatively moving the optical devices could be a solenoid operated device. a magnetostrictive device, or a thermal or pressure sensing device.
Preferably, each optical fibre light guide includes a lens element adapted to transform light flux into a form having a large crosssectional area and a small divergence. Appropriate lens elements are described in our Patent No. 1429843.
The optical apparatus of the present invention can be used in telephone exchanges and data lines. e.g. data highways. in which information is to be conveyed optically along optical fibre light guides. The optical apparatus of the invention can be used with both single and multiple optical fibre lighiguides and can also be used simultaneously over a large range of optical wavelengths.
By using devices such as the piezoelectric device for moving the optical devices towards and away from each other, only an extremely low power consumption is required. Still further. only minimal voltage is normally required since the movement required to separate the optical devices is extremely small and is preferably only a fraction of a wavelength, e.g. a quarter of a wavelength.
Embodiments of the invention will now be described solely by way of example and with reference to the drawing accompanying the provisional specification which shows optical apparatus in accordance with the invention.
Referring to the drawing, there is shown optical apparatus 2 for switching light between four optical fibre light guides 4, 6, 8.
10. Each light guide terminates in a lens element 12 which is capable of transforming the light flux in the light guides into a beam having a large cross-sectional area and a small divergence. If the lens elements 12 are not employed, then the light beam from the light guides 4, 6, 8, 10 tends to diverge and some of it may be lost before it strikes the pair of optical devices 14, 16 which are shown as half-cubes.
The optical devices 14, 16 have, respectively, planar facing surfaces 18, 20. The device 16 is fixed in position whilst the device 14 is adapted to be moved towards and away from the device 16 by means of a piezoelectric actuator 22 which is operatively attached to the device 14. By appropriately energising the piezoelectric actuator 22, the device 14 can be moved towards the device 16 until the planar surfaces 18, 20 are touching. In this position, light can pass in a straight line through the pair of devices 14, 16. Thus, for example. light from the light guide 4 can pass to the light guide 8 (and vice versa) and light from the light guide 6 can pass to the light guide 10 (and vice versa).
When the planar surfaces 18, 20 are apart as shown in the drawings, for example 250nm apart, the optical devices 14, 16 totally internally reflect any light beam that shines on them. Thus light from the light guide 4 can now pass to the light guide 6 (and vice versa) and light from the light guide 8 can pass to the light guide 10 (and vice versa).
The piezoelectric actuator 22 can be such that it is either in its energised or deenergised state when the planar surfaces 18.
20 are in contact with each other. Switching speeds of the order of tens of microseconds may be achievable.
It is to be appreciated that the embodiment of the invention described above has been given by way of example only and that modifications may be effected. Thus. for example. the lens elements 12 could be dispensed with. Also, the planar surfaces 18.
20 could be separated by a distance less than 250 nm in which case some of the light would be reflected by the devices 14. 16 and some of the light would pass straight through the devices 14. 16. In this application. it will be apparent that the optical apparatus is acting as a variable light coupler. Further, instead of moving the device 14, the device 16 could be moved or both devices 14, 16 could be moved.
If the opposing faces of the prisms 18, 20 are ground or formed so as to be as optically flat as possible problems may be experienced in that there is a tendency for such surfaces tò stick together, thus preventing high speed operation of the apparatus.
If it possible to obviate this difficulty by sputtering or similarly depositing a thin film of noble metal on at least one of the opposing faces. If too thick a layer is deposited this will, however, seriously lower the efficiency of the prism. Alternatively, other known release agents may be used.
WHAT WE CLAIM IS: 1. Optical apparatus for switching or variably coupling light between a plurality of optical fibre light guides comprising two optical devices which are relatively movable into and out of contact with each other and a plurality of optical fibre light guides arranged around the two optical devices with their ends spaced from and their axes passing through the two optical devices, the two optical devices being constructed such that when they are in contact light from any of the light guides continues to pass along its axis straight through the two optical devices, and when the two optical devices are not in contact with each other light from any of the light guides is at least partially reflected through an angle by one of the optical devices.
2. Optical apparatus as claimed in claim I in which each optical device is capable of totally internally reflecting light when the two optical devices are not in contact with each other.
3. Optical apparatus as claimed in claim I or claim 2 in which the optical devices are
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (1)

  1. **WARNING** start of CLMS field may overlap end of DESC **.
    Preferably, each optical fibre light guide includes a lens element adapted to transform light flux into a form having a large crosssectional area and a small divergence. Appropriate lens elements are described in our Patent No. 1429843.
    The optical apparatus of the present invention can be used in telephone exchanges and data lines. e.g. data highways. in which information is to be conveyed optically along optical fibre light guides. The optical apparatus of the invention can be used with both single and multiple optical fibre lighiguides and can also be used simultaneously over a large range of optical wavelengths.
    By using devices such as the piezoelectric device for moving the optical devices towards and away from each other, only an extremely low power consumption is required. Still further. only minimal voltage is normally required since the movement required to separate the optical devices is extremely small and is preferably only a fraction of a wavelength, e.g. a quarter of a wavelength.
    Embodiments of the invention will now be described solely by way of example and with reference to the drawing accompanying the provisional specification which shows optical apparatus in accordance with the invention.
    Referring to the drawing, there is shown optical apparatus 2 for switching light between four optical fibre light guides 4, 6, 8.
    10. Each light guide terminates in a lens element 12 which is capable of transforming the light flux in the light guides into a beam having a large cross-sectional area and a small divergence. If the lens elements 12 are not employed, then the light beam from the light guides 4, 6, 8, 10 tends to diverge and some of it may be lost before it strikes the pair of optical devices 14, 16 which are shown as half-cubes.
    The optical devices 14, 16 have, respectively, planar facing surfaces 18, 20. The device 16 is fixed in position whilst the device 14 is adapted to be moved towards and away from the device 16 by means of a piezoelectric actuator 22 which is operatively attached to the device 14. By appropriately energising the piezoelectric actuator 22, the device 14 can be moved towards the device 16 until the planar surfaces 18, 20 are touching. In this position, light can pass in a straight line through the pair of devices 14, 16. Thus, for example. light from the light guide 4 can pass to the light guide 8 (and vice versa) and light from the light guide 6 can pass to the light guide 10 (and vice versa).
    When the planar surfaces 18, 20 are apart as shown in the drawings, for example 250nm apart, the optical devices 14, 16 totally internally reflect any light beam that shines on them. Thus light from the light guide 4 can now pass to the light guide 6 (and vice versa) and light from the light guide 8 can pass to the light guide 10 (and vice versa).
    The piezoelectric actuator 22 can be such that it is either in its energised or deenergised state when the planar surfaces 18.
    20 are in contact with each other. Switching speeds of the order of tens of microseconds may be achievable.
    It is to be appreciated that the embodiment of the invention described above has been given by way of example only and that modifications may be effected. Thus. for example. the lens elements 12 could be dispensed with. Also, the planar surfaces 18.
    20 could be separated by a distance less than 250 nm in which case some of the light would be reflected by the devices 14. 16 and some of the light would pass straight through the devices 14. 16. In this application. it will be apparent that the optical apparatus is acting as a variable light coupler. Further, instead of moving the device 14, the device 16 could be moved or both devices 14, 16 could be moved.
    If the opposing faces of the prisms 18, 20 are ground or formed so as to be as optically flat as possible problems may be experienced in that there is a tendency for such surfaces tò stick together, thus preventing high speed operation of the apparatus.
    If it possible to obviate this difficulty by sputtering or similarly depositing a thin film of noble metal on at least one of the opposing faces. If too thick a layer is deposited this will, however, seriously lower the efficiency of the prism. Alternatively, other known release agents may be used.
    WHAT WE CLAIM IS:
    1. Optical apparatus for switching or variably coupling light between a plurality of optical fibre light guides comprising two optical devices which are relatively movable into and out of contact with each other and a plurality of optical fibre light guides arranged around the two optical devices with their ends spaced from and their axes passing through the two optical devices, the two optical devices being constructed such that when they are in contact light from any of the light guides continues to pass along its axis straight through the two optical devices, and when the two optical devices are not in contact with each other light from any of the light guides is at least partially reflected through an angle by one of the optical devices.
    2. Optical apparatus as claimed in claim I in which each optical device is capable of totally internally reflecting light when the two optical devices are not in contact with each other.
    3. Optical apparatus as claimed in claim I or claim 2 in which the optical devices are
    glass or silica prisms.
    4. Optical apparatus as claimed in claim 1 or claim 2 in which the optical devices are transparent plastics prisms.
    5. Optical apparatus as claimed in any one of claims 1 to 4 including means for relatively moving the optical devices into and out of contact with each other in response to a control signal.
    6. Optical apparatus as claimed in claim 5 in which said means for relatively moving the optical devices is a piezoelectric actuator.
    7. Optical apparatus as claimed in claim 5 in which said means for relatively moving the optical devices is a solenoid operated device.
    8. Optical apparatus as claimed in claim 5 in which the means for relatively moving the optical devices is a thermal or pressure sensing device.
    9. Optical apparatus as claimed in any one of claims 1 to 8 in which each optical fibre light guide has a lens element attached to its end to collimate light emitted by the fibre,
    10. Optical apparatus substantially as described with reference to the drawing accompanying the provisional specification.
GB5328276A 1977-12-20 1977-12-20 Opitcal apparatus for switching or variably coupling light between a plurality of optical fibre light guides Expired GB1594336A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB5328276A GB1594336A (en) 1977-12-20 1977-12-20 Opitcal apparatus for switching or variably coupling light between a plurality of optical fibre light guides

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB5328276A GB1594336A (en) 1977-12-20 1977-12-20 Opitcal apparatus for switching or variably coupling light between a plurality of optical fibre light guides

Publications (1)

Publication Number Publication Date
GB1594336A true GB1594336A (en) 1981-07-30

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0057164A2 (en) * 1981-01-22 1982-08-04 SELENIA INDUSTRIE ELETTRONICHE ASSOCIATE S.p.A. Device for coupling a laser beam to a fibre optic
FR2517484A2 (en) * 1981-05-08 1983-06-03 Comp Generale Electricite Variable frequency high pressure carbon di:oxide laser - has two nearby contra-rotating prisms successively traversed by diffracted radiation
DE3608134A1 (en) * 1986-03-12 1987-09-24 Ant Nachrichtentech Optical switch
DE4101791C1 (en) * 1991-01-23 1991-12-05 Ant Nachrichtentechnik Gmbh, 7150 Backnang, De
GB2253923A (en) * 1991-03-07 1992-09-23 Mitsubishi Materials Corp Piezoelectric actuator to [un]block or redirect light path
US5208880A (en) * 1992-04-30 1993-05-04 General Electric Company Microdynamical fiber-optic switch and method of switching using same
EP0592902A1 (en) * 1992-10-05 1994-04-20 KE KOMMUNIKATIONS-ELEKTRONIK GMBH & CO Optical device having variable light transmission
WO2003001273A1 (en) * 2001-06-21 2003-01-03 INSTITUT FüR MIKROTECHNIK MAINZ GMBH Optical switching device

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0057164A3 (en) * 1981-01-22 1982-08-25 Selenia Industrie Elettroniche Associate S.P.A. Perfected device for coupling a laser beam to a fibre optic
EP0057164A2 (en) * 1981-01-22 1982-08-04 SELENIA INDUSTRIE ELETTRONICHE ASSOCIATE S.p.A. Device for coupling a laser beam to a fibre optic
FR2517484A2 (en) * 1981-05-08 1983-06-03 Comp Generale Electricite Variable frequency high pressure carbon di:oxide laser - has two nearby contra-rotating prisms successively traversed by diffracted radiation
DE3608134A1 (en) * 1986-03-12 1987-09-24 Ant Nachrichtentech Optical switch
EP0496224A3 (en) * 1991-01-23 1993-01-20 Ant Nachrichtentechnik Gmbh Optical change-over switch
DE4101791C1 (en) * 1991-01-23 1991-12-05 Ant Nachrichtentechnik Gmbh, 7150 Backnang, De
EP0496224A2 (en) * 1991-01-23 1992-07-29 ANT Nachrichtentechnik GmbH Optical change-over switch
GB2253923A (en) * 1991-03-07 1992-09-23 Mitsubishi Materials Corp Piezoelectric actuator to [un]block or redirect light path
GB2253923B (en) * 1991-03-07 1994-05-04 Mitsubishi Materials Corp An optical switch
US5208880A (en) * 1992-04-30 1993-05-04 General Electric Company Microdynamical fiber-optic switch and method of switching using same
EP0569187A1 (en) * 1992-04-30 1993-11-10 General Electric Company Microdynamic fiber-optic switch
EP0592902A1 (en) * 1992-10-05 1994-04-20 KE KOMMUNIKATIONS-ELEKTRONIK GMBH & CO Optical device having variable light transmission
WO2003001273A1 (en) * 2001-06-21 2003-01-03 INSTITUT FüR MIKROTECHNIK MAINZ GMBH Optical switching device

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