Connection means for optical fibres

The present invention relates to an optical connection means arranged in order to rearrange and connect optical fibers connected to the connection means. In order to simplify handling of optical fiber ribbons, so-called fiber ribbons, an optical connection means with an integrated cross-connection (2) has been produced with which component optical fibers (3) connected to the component can be rearranged such as cross-connected and connected via an interface (4). With an optical cross-connection of the "sidings" type integrated with a so-called MT-connector interface from for example a four-fiber transmitter array and a four-fiber receiver array an eight-fiber MT-connector interface with alternate transmitter respective receiver fibers next to each other can be obtained.

TECHNICAL FIELD
 The present invention relates to an optical connection means arranged to be
 able to rearrange and connect optical fibres connected to the connection
 means.
 STATE OF THE ART
 From EP-0 458 608 A1 is known a connecting means for optical fibres having
 an integrated optical circuit which permits a reconfiguration of an
 optical system in the connection means.
 DESCRIPTION OF THE INVENTION
 In order to simplify the handling of optical fibre ribbons, so called fibre
 ribbons, a component, an optical connection means, a so called
 MT-connector with integrated cross-connections has been developed, with
 which component optical fibres connected to the component can be
 rearranged e.g. cross-connected and connected via an interface. The
 invention will be described more closely with the help of preferred
 embodiments and with reference to the accompanying figures.
 Today developments are heading towards more cost effective solutions at the
 circuit board level, e.g. four transmitters such as laser transmitters or
 four receivers can be built together on a single chip, a so called array.
 Such chips in turn can be encapsulated in a single capsule and in this
 case a four channel array transmitter or receiver can be obtained well
 packaged for mounting on a circuit board. During allocation to a
 subscriber it is desirable to be able to draw out a fibre from each of a
 transmitter and a receiver and consequently to obtain a bi-directional
 two-fibre link where the transmitter fibre and receiver fibre lie
 immediately beside each other. In order to obtain this configuration a
 sort of optical cross coupling of the "sidings" type is required. With
 such a "sidings" integrated with a so-called MT-connector interface from
 for example a four-fibre transmitter array and a four-fibre receiver array
 an eight-fibre MT-connection interface can be obtained with alternating
 transmitter respective receiver fibres next to each other. The cross
 connecting itself--"sidings"--can either be integrated completely in the
 connector itself or can be inside a lengthened break protection in direct
 connection to the connector.

PREFERRED EMBODIMENTS
 The optical connection means 1 can, like in FIG. 1, be an eight-fibre
 MT-connector, essentially consisting of a plastic casing surrounding the
 rearranged optical fibres like the cross-connected optical fibres 2, and
 having the free optical fibre ends 3 of the optical fibres connected to
 the plastic casing on one side and an optical fibre interface 4 on the
 other side of the connection means. The optical fibre ribbon ends can
 consequently be connected to the optical fibre interface 4 on the
 connection means and reconfigured or cross-connected output optical fibres
 can be obtained from the connecting means.
 FIG. 1 shows simplified how an eight-fibre MT-connector with the integrated
 optical cross-connection 2 can appear. The placement of the integrated
 cross-connection 2 depends on the existing space in the casing of the
 connector, if the cross-connection of the optical fibres is glued into the
 connector or if the connector is moulded directly onto the optical fibres
 and the cross-connection, but does not form any limitation and
 four-equally 12-optical fibres can be comprised in the concept according
 to the above. In the figure a break protection 5 connected to the
 MT-connector on the front side and an interface 4 with free optical fibre
 ends on the rear side are also shown. The connector also has parallel
 circular guide holes 6 and 7 for the accurate alignment and fastening of
 the connector with the guide pins on a contact connector.
 FIG. 2 shows how the input eight-fibre ribbon has been divided into
 2.times.4 fibres/four-fibre ribbons 8 and 9 where one of the four-fibre
 ribbons 8 is intended to be connected to a four-channel array receiver
 module and the other four-fibre ribbon 9 is intended to be connected to a
 four-channel array transmitter module.
 In FIG. 3 the MT-connector is shown from the other side 10 with the so
 called MT-8 connector interface 4 where alternate fibres are transmitters
 and alternate fibres are receivers.
 FIG. 4 shows an alternative embodiment of a connection means 11 according
 to the invention with an integrated cross-connection 13 and with
 MT-connection interfaces 14 and 15 at both ends. With this connection
 means a fibre ribbon with an MT-connection interface is connected to the
 connection means whereby the connected optical fibres will be
 cross-connected in the connection means and during connection to e.g. a
 four-channel transceiver capsule with an MT-8 interface dividing up into a
 transmitter side and a receiver side can be obtained. The connection means
 can be aligned with its guide holes 16 and 17 with guide pins/guide pegs
 and fastened onto e.g. the transceiver capsule with some type of snap
 fastening or metal plate or the like. A cross-connecting component
 according to the above with an MT-connector interface at each end and with
 integrated cross-connection can be manufactured through direct moulding of
 the connector body around the cross-connected fibres.
 The use of fibre ribbons in combination with ribbon welding and optical
 connection means simplifies the work considerably during the installation
 of fibre optical networks. It is especially important in access networks
 where the cost determines when the optical fibre can be drawn all the way
 home to the subscriber (FTTH, Fibre To The Home). It is therefore
 desirable to be able to retain the fibre ribbon undivided even during
 cross-connection or other rearranging of the optical fibres.
 The use of the optical connection means with fibre ribbons is advantageous
 when for example there is a requirement for cross-connection or other
 rearranging of signals from transmitter- and receiver arrays on an
 electronic board.
 An optical connection means according to the invention can be manufactured
 starting from a suitable number of fibre ribbons one end of which have
 been joined together, liberated and rearranged e.g. cross-connected. The
 joined-together and rearranged optical fibres are fixed in the connection
 means through for example baking-in in plastic, whereby the
 cross-sectional surfaces of the fibre ends in the interface form the
 optical interface of the fibre end surfaces of the connected fibre
 ribbons. A fibre organiser can be used to organise the optical fibres in
 the optical connection means. The cross-connection zone, mixing point or
 weave zone formed can then be encapsulated between two casings possibly
 filled with an elastic material.
 The invention is naturally not limited to the embodiments described above
 and shown in the drawings but can be modified within the scope of the
 accompanying patent claims.