CN201364403Y

CN201364403Y - Optical receiving component used for optical network terminal

Info

Publication number: CN201364403Y
Application number: CNU2009201351781U
Authority: CN
Inventors: 朱利军; 周永华; 曹龙贵
Original assignee: Shenzhen Neo Photonic Technology Co Ltd
Current assignee: Shenzhen Neo Photonic Technology Co Ltd
Priority date: 2009-03-06
Filing date: 2009-03-06
Publication date: 2009-12-16
Anticipated expiration: 2019-03-06

Abstract

The utility model provides an optical receiving component used for an optical network terminal, comprising an optical signal group formed by inputting at least two paths of optical signals with same wave length, a combined lens and a photoelectric diode; the combined lens converges light of the optical signal group to the photoelectric diode which receives and converts the light into electric signals; the combined lens is injected into an integrated forming lens and comprises an incident light end surface and an emergent light end surface, wherein the incident light end surface is provided with an array of a plurality of small lens bosses corresponding to input optical paths; and the emergent light end surface is provided with a large lens boss; each path of input optical signals respectively enter into the raised surface of the small lens corresponding to the input signals; all the beams after all paths of optical signals enter are converged to the photoelectric diode chip by the large lens boss of the emergent light end surface. One photoelectric diode can receive a plurality of paths of input optical signals simultaneously, and each path of optical signals can be converged to a unique photoelectric diode chip with approximate zero loss by the combined lens so as to realize photoelectric conversion.

Description

A kind of optical receiving component for optical network terminal

Technical field

The utility model relates to the ONT Optical Network Terminal OLT (Optical line terminal) of a kind of EPON (PON, Passive optical Network) system, relates in particular to the optical receiving component for optical network terminal in the PON system.

Background technology

Technology of Light Access Network especially the application of PON passive optical network technique bandwidth characteristic, the low cost of access way, high power capacity have obtained development at a high speed flexibly with it.FTTH is divided three classes in the design of transport layer, is respectively two fine two way circuit, single fiber bi-directional loop and single fiber three-way loops.Wherein two fine two way circuits are to use two-way optical fiber to connect between OLT end and ONU end, and one the tunnel is descending, and signal is held the ONU end by OLT, and another road is up, and signal is held the OLT end by ONU, in two fine loops up and down the provisional capital use the 1310nm wave band to transmit signal.The single fiber bi-directional loop is called Bidirectional again, be called for short BiDi, this scheme only uses an optical fiber to connect OLT end and ONU end, and utilize the WDM mode, transmit the signal of uplink and downlink respectively with wavelength optical signals, as shown in Figure 1, adopt single fiber bi-directional loop wavelength-division multiplex technique scheme (descending 1490nm, up 1310nm), the OLT module generally is placed on end office's machine room of operator, this module adopts the single fiber bi-directional integrated module of optical transceiver, comprise a single fiber, one emitting module, one receiving unit and a WDM wave filter, only need a trunk optical fiber between OLT module and the optical branching device Splitter, its transmission range can reach 20 kilometers, each branch road of the output terminal of optical branching device Splitter connects an ONU user, and the number of users that each optical branching device Splitter connects can reach 32 at most, therefore can reduce the cost pressure of OLT and trunk optical fiber greatly.By optical branching device Splitter optical signal transmission is held (user side) to a plurality of ONU at the OLT end, do not need node device at optical branch point, no longer through amplifying and regeneration, the branch route Splitter of network realizes light signal in transmission course.The optical branching device Splitter splitting ratio that generally uses in the PON system is 1 at present: the N road, the following biography light signal that is about to the OLT end is dispensed to N road ONU optical network unit, on the contrary, the light signal of being uploaded by N road ONU optical network unit closes ripple by this optical branching device Splitter again and holds to OLT.OLT, the optical parameter of ONU: emissive power :+2dB is to+6dB; Receiving sensitivity-26dB; Fibre loss: 0.3dB/ kilometer; The optical branching device loss, the optical loss of 1 * n optical branching device :=10log (1/n) in theory, optical branching device loss-3dB as 1 * 2; Optical branching device loss-6dB of 1 * 4; Optical branching device loss-9dB of 1 * 8; Optical branching device loss-12dB of 1 * 16; Optical branching device loss-15dB of 1 * 32; Optical branching device loss-18dB of 1 * 64; Optical branching device loss-21dB of 1 * 128.In the practice, approximately have the added losses of 2dB because of manufacturing factor and junction loss.Generally speaking, taking descending optical wavelength is 1490nm and up optical wavelength is 1310nm.Optical fiber property is when the 1310nm light signal that transmits more than 20 kilometers, and its loss is greater than the 1490nm light signal.Because non-equilibrium loss between up-downgoing, cause defining the size of the splitting ratio of optical branching device.In the PON system, OLT end module cost accounts for maximum deal in total system, and OLT quantity is many more, and system cost is just high more.

Summary of the invention

The utility model provides a kind of low-cost optical receiving component for optical network terminal.

For realizing above goal of the invention, the utility model provides a kind of optical receiving component for optical network terminal, comprising: the optical signal set that same wavelength is formed by the two-way input at least; One compound lens and a photodiode, described optical signal set converges to described photodiode chip by described compound lens with light and receives and be converted to electric signal.

Described compound lens is the integrated through injection molding molded lens, these lens comprise: incident light end face and emergent light end face, its incident light end face is provided with the array with the corresponding a plurality of lenslet projectioies of described input light path, described emergent light end face is provided with a big lens projection, every road input optical signal is incident to the lenslet convex surfaces corresponding with it respectively, and the light beam after each road light signal incident all converges to described photodiode chip by the big lens projection of emergent light end face.

The a plurality of lenslets of the incident light end face of described integrated through injection molding molded lens and the big lens of emergent light end face are non-globe lens.

Described input optical signal is four the tunnel, and by four single fiber inputs, the lenslet projection of the incident light end face of described lens combination is four respectively.

In the optical fiber receive module of said structure, a photodiode can receive the multichannel input optical signal simultaneously, and every road light signal can both be realized opto-electronic conversion to converge on unique photodiode chip by compound lens near zero loss ground.The optical fiber receive module of this multipath light signal input can make the PON system reach balance in up 1310nm and descending 1490nm wavelength transmitted in both directions, thereby can effectively increase the number of users of OLT output terminal.

Description of drawings

Fig. 1 represents single fiber bi-directional transmission light path synoptic diagram in the prior art PON system;

Fig. 2 represents the light path principle synoptic diagram of the utility model optical fiber receive module;

Fig. 3 represents the perspective view of compound lens shown in Figure 2;

Fig. 4 represents the decomposing schematic representation of optical fiber receive module shown in Figure 2;

Fig. 5 represents the diagrammatic cross-section of optical fiber receive module shown in Figure 4.

Fig. 6 represents that the utility model optical fiber receive module is applied to the light path synoptic diagram of OLT end in the PON system.

Embodiment

Describe the utility model most preferred embodiment in detail below in conjunction with accompanying drawing.

Optical receiving component for optical network terminal comprises: form optical signal set 1 by the two-way input at least by same wavelength as shown in Figure 2; One compound lens 2 and a photodiode 3.Compound lens 2 as shown in Figure 3 is the integrated through injection molding molded lens, these lens comprise: incident light end face and emergent light end face, its incident light end face is provided with and imports the array of light number corresponding a plurality of lenslet projectioies 21, the emergent light end face is provided with a big lens projection 22, every road input optical signal is incident to the lenslet corresponding with it projection 21 surfaces respectively, and the light beam after each road light signal incident all converges to photodiode 3 chips by the optical surface of the big lens projection 22 of emergent light end face and receives to realize the conversion of photosignal.Among this embodiment, optical signal set 1 is four tunnel inputs, and 21 of the lenslet projectioies of the incident light end face of compound lens 2 are four.As shown in Figure 4 and Figure 5, from four road up input optical signals of light subscriber unit ONU, its wavelength is 1310nm, respectively by 4 inputs of four single fibers in the lock pin holder 5, with compound lens 2, the outer sleeve three of lens mount and lock pin holder 5 is injection molded into integrally formed complex plastic member 6, these member two ends are the casing joint shape, compound lens 2 is wherein built-in, during installation, one end casing joint of this compound plastic member 6 is used to install and fix photodiode 3, other end casing joint is used for fixing lock pin holder 5, makes the optical signal set of optical fiber 4 inputs receive the optical fiber receive module of realizing the input of four road single fibers with this by fixed light electric diode 3 after compound lens 2 converges.

Represent that as Fig. 6 the optical fiber receive module of the utility model structure is applied to the technical scheme of 1 minute 128 tunnel PON system, OLT end module comprises a common light emission group device TOSA, and its optical fiber receive module adopts the optical fiber receive module ROSA of the utility model multichannel input structure.Light emission group device is by single fiber transmitting downstream 1490nm light signal to one 1: 4 optical branching device Splitter, its four shunt respectively connect 1: 32 optical branching device Splitter, each respectively connects a smooth subscriber unit ONU along separate routes again, makes descending 1490nm light signal be dispensed to 128 light subscriber unit ONU.When up, each ONU transmits the light signal of up 1310nm to OLT by connected 1: 32 optical branching device Splitter, simultaneously, the rear end of 1: 4 optical branching device Splitter is provided with a WDM wavelength division multiplexer, the 1490nm light signal that this channel-splitting filter transmission is descending, this each up road light signal all receives by inputing to optical fiber receive module ROSA after this WDM wavelength division multiplexer reflection, realizes 1 minute 128 tunnel PON system of low-cost highly sensitive reception.

Claims

1, a kind of optical receiving component for optical network terminal is characterized in that, comprising: the optical signal set that same wavelength is formed by the two-way input at least; One compound lens and a photodiode, described optical signal set converges to described photodiode chip by described compound lens with light and receives and be converted to electric signal.

2, optical receiving component for optical network terminal according to claim 1, it is characterized in that, described compound lens is the integrated through injection molding molded lens, these lens comprise: incident light end face and emergent light end face, its incident light end face is provided with the array with the corresponding a plurality of lenslet projectioies of described input light path, described emergent light end face is provided with a big lens projection, every road input optical signal is incident to the lenslet convex surfaces corresponding with it respectively, and the light beam after each road light signal incident all converges to described photodiode chip by the big lens projection of emergent light end face.

3, optical receiving component for optical network terminal according to claim 2 is characterized in that, a plurality of lenslets of the incident light end face of described integrated through injection molding molded lens and the big lens of emergent light end face are non-globe lens.

4, optical receiving component for optical network terminal according to claim 3 is characterized in that, described input optical signal is four the tunnel, and by four single fiber inputs, the lenslet projection of the incident light end face of described lens combination is four respectively.