A kind of EPON system
The present invention relates to PON network, and in particular to a kind of EPON system.
EPON (passive optical network based on Ethernet) is one kind of PON network, is as telecommunication technology develops, to meet
The high rate broadband business demand such as video, data and a kind of Integrated access technology being widely adopted.EPON networks are by OLT, ODN
It is formed with ONU three parts.Point-to-multipoint is mainly characterized by, circuit is passive, and network layer is simply apparent, is capable of providing voice, width
The Integrated access of the multiple business such as band, CATV.At present, it is 1490nm sections the most commonly used is downlink optical signal wavelength in optical fiber transmission
With 1550nm sections, and the wavelength of the optical signal rate of decay in a fiber and optical signal is inversely proportional, that is to say, that wavelength is shorter, declines
Subtract faster, thus the maximum distance of optical signal transmission is determined by 1490nm sections of optical signal；And if whole enhancing mixing
The luminous power of optical signal, and system burden can be increased, easily damage equipment heating.This just needs to be laid with more OLT device,
It is of high cost, hinder the implementation of EPON networks.
The technical problem to be solved in the present invention is to provide a kind of EPON systems, can increase under smaller system burden
The integrated level and coverage area of OLT device reduce and are laid with cost and maintenance cost.
In order to solve the above technical problem, the present invention provides a kind of EPON system, including being located at fiber optic backbone terminal
The light transmit-receive integrated machines of OLT and the ONU positioned at user terminal；It is ONU points that the light transmit-receive integrated machines of OLT, which include signal connection successively,
OLT modules with bandwidth, the wavelength division multiplexer for detaching the optical splitter of different wave length downlink optical signal, compound different wave length optical signal
With the optical transceiver module of convergence distribution optical signal, signal is connected with to amplify light work(between the optical splitter and wavelength division multiplexer
The image intensifer of rate, the optical transceiver module are connected with ONU signals.
As preference, the optical splitter includes anisotropic transparent crystal.
As preference, the anisotropic transparent crystal is calcite or quartz.
As preference, the image intensifer is connected with the short-wave band light path of optical splitter, the wavelength division multiplexer and light splitting
Device long-wave band light path connects.
As preference, the optical transceiver module includes the expand unit for spread homogenizer, converges diffusion light beam
Convergence unit and cross section of optic fibre product etc. rule variation fiber optic bundle, the wavelength division multiplexer, expand unit, convergence unit and
Signal connects fiber optic bundle successively.
As preference, the expand unit is included the concavees lens of beam spread, the convergence unit includes being located at recessed
The focal length of convex lens at lens focus, focal length and concavees lens is identical, and the receipts smooth surface of the fiber optic bundle is located at the coke of convex lens
As preference, diameter of the diameter of the receipts smooth surface of fiber optic bundle not less than the outgoing beam of convergence unit.
As preference, the receipts smooth surface radius of the convergence unit is not less than the focal length of convex lens and the optical fiber angle of total reflection
The product of the sine value of complementary angle.
As preference, the fiber optic bundle include receive light section, it is described receipts light section in optical fiber fan-shaped cross section, the center of circle
Angle gauge then changes, and side is adjacent successively.
As preference, the fiber optic bundle include will receive optical fiber gentle transition fan-shaped in light section for circular changeover portion with
Optical fibre refractivity is in the self-focusing section of square-law distribution.
Compared with prior art, the beneficial effects of the invention are as follows：
1st, the present invention integrates OLT modules and optical transceiver module, increases the integrated level of equipment, reduces equipment
Operation and the cost safeguarded.
2nd, the present invention is separated the optical signal of the different wave length of downlink, and pass through light amplification by setting optical splitter
Device targetedly enhances the optical signal of short wavelength, can increase the farthest transmission range of optical signal, can increase OLT device
Covering radius reduces the cost of installation apparatus；And enhancing optical signal compared to whole, system burden is small.
3rd, the present invention is by equipment wavelength division multiplexer, can make during the optical signal of the different wave length of separation is combined to all the way,
And in middle transmission all the way, reduction cost.
4th, the present invention is by setting optical transceiver module that a branch of downlink optical signal can be divided into the more of different luminous powers
A optical signal to meet the transmission demand of different distance ONU equipment, considerably increases the coverage area of OLT, reduces and be laid to
Description of the drawings
It, below will be in the description of embodiment technology for the clearer technical solution illustrated in technology of the embodiment of the present invention
Required attached drawing is briefly described, it should be apparent that, the accompanying drawings in the following description is only some realities of the present invention
Example is applied, for those of ordinary skill in the art, without creative efforts, additionally it is possible to according to these attached drawings
Obtain other attached drawings.
Fig. 1 is the structural diagram of the present invention；
Fig. 2 is the structure diagram of optical transceiver module；
Fig. 3 is the cross-sectional view for receiving light section；
Fig. 4 is the cross-sectional view of changeover portion.
Wherein, 1- expand units, 2- convergence units, 3- receive light section, 4- changeover portions, 5- self-focusing sections, 6-OLT modules, 7-
Optical transceiver module, 8-ONU, 9- optical splitters, 10- image intensifers, 11- wavelength division multiplexers.
Below in conjunction with the attached drawing in the embodiment of the present invention, the technical solution in the embodiment of the present invention is carried out clear, complete
Whole description, it is clear that described embodiment is only part of the embodiment of the present invention, instead of all the embodiments.It is based on
Embodiment during this is practical, those of ordinary skill in the art are obtained all under the premise of creative work is not made
Other embodiment shall fall within the protection scope of the present invention.
With reference to shown in Fig. 1~Fig. 4, the invention discloses a kind of EPON system, including light transmit-receive integrated machines of OLT and several
The light transmit-receive integrated machine of ONU8, OLT includes OLT modules 6, optical transceiver module 7, optical splitter 9, image intensifer 10 and wavelength division multiplexer
Above-mentioned OLT modules 6 are arranged on fiber optic backbone terminal, are that ONU8 sends Ethernet data with broadcast mode, initiates
And control ranging process, and record ranging information and for ONU8 bandwidth allocations, that is, control ONU8 transmission datas initial time and
Send window size.
Above-mentioned optical splitter 9 is connected with 6 signal of OLT modules, including anisotropic transparent crystal, is used for 1490nm
Section is detached with 1550nm sections of downlink optical signals.Anisotropic transparent crystal can be calcite or quartz.
Above-mentioned image intensifer 10 and wavelength division multiplexer 11 are both connected on optical splitter 9.Under the 1490nm sections that optical splitter 9 detaches
Traveling optical signal carries out the amplification of luminous power via image intensifer 10；1490nm section downlink optical signals after power amplification and
1550nm sections of downlink optical signal carried out via wavelength division multiplexer 11 it is compound, obtain enhancing 1490nm sections of downlink optical signals mixing
Optical signal.Optical transceiver module 7 and wavelength division multiplexer 11 connect, and mixing optical signal is incident in optical transceiver module 7.
Above-mentioned optical transceiver module 7 includes expand unit 1, convergence unit 2 and fiber optic bundle.
Above-mentioned expand unit 1 is connected with 11 signal of wavelength division multiplexer, including concavees lens.Concavees lens can be by wavelength-division multiplex
The incident beam with signal that device 11 is sent out uniformly is spread.
Above-mentioned convergence unit 2 is connected with 1 signal of expand unit, including convex lens.Convex lens is located at the focus of concavees lens
Place, the focal length of convex lens is identical with the focal length of concavees lens, can converge diffusion light beam that expand unit 1 is sent out, and from remittance
The parallel injection of exit facet of poly- unit 2.
Above-mentioned fiber optic bundle includes receiving light section 3, changeover portion 4 and self-focusing section 5.The receipts smooth surface for receiving light section 3 is located at convex lens
Focal point.Receive optical fiber in light section 3 and centerline axis parallel, fan-shaped cross section for optical fiber, and fan-shaped central angle rule becomes
Change, fan-shaped side is adjacent successively, and fan-shaped arc forms complete circumference.The diameter of light section 3 is received not less than convergence 2 emergent light of unit
The diameter of beam.The central angle for receiving different optical fiber in light section 3 can be arithmetic progression, Geometric Sequence etc., be received according to ONU8 and light
The characteristic distributions of the distance of module 7 are sent out to determine；For example, if ONU8 is respectively positioned on the identical position of optical transceiver module 7,
The central angle of optical fiber is equal, if the distance of ONU8 and optical transceiver module 7 gradually increases, the central angle of optical fiber gradually increases.It receives
Fan-shaped optical fiber in light section 3 can receive the outgoing beam from convergence unit 2 completely, and the utilization rate of light beam is high；Fan-shaped optical fiber
Central angle rule variation so that optical fiber receipts light area rule variation, so as to obtain different luminous powers, for nearer
ONU8 is then using the smaller fibre circuit of central angle, for ONU8 farther out then using the larger fibre circuit of central angle.Receive light
Section 3 can distribute luminous power according to the distance of ONU8, in the case where ensureing optical signal along original circuit normal transmission, Neng Gouzeng
The farthest transmission range of big optical signal, reduces laying cost, accelerates the universal of fibre optic data transmission.Changeover portion 4 is arranged on receipts
The exit facet of light section 3, it is circular optical fiber that will receive the transition that fan-shaped optical fiber is gentle in light section 3, with subsequent optical fiber pair
It connects.The light-emitting surface of changeover portion 4 is removably arranged on the plane of incidence of self-focusing section 5, can be according to the distribution situation of ONU8 reality
It replaces and receives light section 3 and changeover portion 4, increase the versatility of equipment.The optical fiber of self-focusing section 5 receives the fiber alignment in light section 3.Autohemagglutination
The optical fibre refractivity of burnt section 5 is distributed in square-law, can focus on light beam automatically, to increase the luminous power in unit area,
Increase the transmission range of optical signal.It is connected between self-focusing section 5 and ONU8 by optical fiber.
The transmission path of uplink optical signal can be the reverse of the transmission path of above-mentioned downlink optical signal.Converge 2 He of unit
The radius of the adjacent receipts smooth surface of fiber optic bundle is not less than the product of the sine value of the focal length of convex lens and the complementary angle of the optical fiber angle of total reflection,
When the light beam in fiber optic bundle is emitted with maximum shooting angle, it can still be incident in convergence unit 2, improve utilization ratio.
The foregoing description of the disclosed embodiments enables professional and technical personnel in the field to realize or use the present invention.
A variety of modifications of these embodiments will be apparent for those skilled in the art, it is as defined herein
General Principle can be realized in other embodiments without departing from the spirit or scope of the present invention.Therefore, it is of the invention
The embodiments shown herein is not intended to be limited to, and is to fit to consistent with principles disclosed herein and novel point
Most wide range.