WO2010121463A1 - 一种兼容两种无源光网络的波分复用器 - Google Patents

一种兼容两种无源光网络的波分复用器 Download PDF

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Publication number
WO2010121463A1
WO2010121463A1 PCT/CN2009/074200 CN2009074200W WO2010121463A1 WO 2010121463 A1 WO2010121463 A1 WO 2010121463A1 CN 2009074200 W CN2009074200 W CN 2009074200W WO 2010121463 A1 WO2010121463 A1 WO 2010121463A1
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WO
WIPO (PCT)
Prior art keywords
band
filter
upgrade
transmission
reflection
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PCT/CN2009/074200
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English (en)
French (fr)
Inventor
朱松林
耿丹
苏婕
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中兴通讯股份有限公司
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Application filed by 中兴通讯股份有限公司 filed Critical 中兴通讯股份有限公司
Priority to US13/257,991 priority Critical patent/US8655174B2/en
Priority to EP09843567.0A priority patent/EP2424140B1/en
Publication of WO2010121463A1 publication Critical patent/WO2010121463A1/zh

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0226—Fixed carrier allocation, e.g. according to service
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0228—Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths
    • H04J14/023—Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths in WDM passive optical networks [WDM-PON]
    • H04J14/0232—Wavelength allocation for communications one-to-all, e.g. broadcasting wavelengths in WDM passive optical networks [WDM-PON] for downstream transmission
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0241—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
    • H04J14/0242—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON
    • H04J14/0245—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON for downstream transmission, e.g. optical line terminal [OLT] to ONU
    • H04J14/0246—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON for downstream transmission, e.g. optical line terminal [OLT] to ONU using one wavelength per ONU
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0241—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
    • H04J14/0242—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON
    • H04J14/0245—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON for downstream transmission, e.g. optical line terminal [OLT] to ONU
    • H04J14/0247—Sharing one wavelength for at least a group of ONUs
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0241—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
    • H04J14/0242—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON
    • H04J14/0249—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON for upstream transmission, e.g. ONU-to-OLT or ONU-to-ONU
    • H04J14/025—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON for upstream transmission, e.g. ONU-to-OLT or ONU-to-ONU using one wavelength per ONU, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0227—Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
    • H04J14/0241—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths
    • H04J14/0242—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON
    • H04J14/0249—Wavelength allocation for communications one-to-one, e.g. unicasting wavelengths in WDM-PON for upstream transmission, e.g. ONU-to-OLT or ONU-to-ONU
    • H04J14/0252—Sharing one wavelength for at least a group of ONUs, e.g. for transmissions from-ONU-to-OLT or from-ONU-to-ONU
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0278—WDM optical network architectures
    • H04J14/0282—WDM tree architectures
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0201—Add-and-drop multiplexing

Definitions

  • Wavelength division multiplexer compatible with two passive optical networks
  • the present invention relates to a Next Generation-Passive Optical Network (Time Generation Multiplexing (TDM) and Wavelength Division Multiplexing (WDM) technology combined in the optical access network communication field.
  • NG-PON Next Generation-Passive Optical Network
  • TDM-PON Time Division Multiplexing-Passive Optical Network
  • ATM-PON Broadband-PON
  • Ethernet-PON Ethernet-PON
  • Gigabit-PON Gigabit-PON
  • the optical access network is based on the current Broadband Passive Optical Network (B-PON) based on time division multiplexing technology, Gigabit Passive Optical Network (G-PON), and Ethernet passive.
  • B-PON Broadband Passive Optical Network
  • G-PON Gigabit Passive Optical Network
  • Ethernet passive Optical Passive Optical Network
  • E-PON has gradually evolved into a multi-wavelength and high-rate next-generation passive optical network based on time division multiplexing and wavelength division multiplexing.
  • the bidirectional high-speed transmission of a single-fiber multi-wavelength between an optical line terminal (OLT) and an optical network unit (ONU) greatly improves the utilization of the fiber.
  • the S-band ranges from 1480 ⁇ to 1500 ⁇ , in order to coexist with the NG-PON, the upstream O-band.
  • the range is from 1290 nm to 1330 nm.
  • the optical line terminal of the existing time-division multiplexed passive optical network is called the legacy optical line terminal (legacy OLT), and its working band is the base band.
  • the next-generation passive optical network optical line terminal is called the Upgrade Optical Line Terminal (Upgrade OLT).
  • the Full Service Access Networks (FCA) organization plans the wavelengths of next-generation passive optical networks with upstream wavelengths ranging from 1260 nm to 1280 nm and downstream wavelengths ranging from 1575 nm to 1580 nm.
  • the downstream signal of CATV has a wavelength range of 1550 nm to 1560 nm.
  • WDM1 is inserted between the optical line terminal, the upgraded optical line terminal and the splitter (Wavelength Division Multiplexingl, WDM1, specified in G.984.5: for implementing the next generation passive optical network and the existing time division multiplex passive
  • WDM1 The name of the optical network compatible wavelength division multiplexer is WDM1
  • WDM1 enables the optical distribution network of the existing TDM-PON to simultaneously transmit the optical signals of the NG-PON, thereby achieving a smooth upgrade of the TDM-PON to the NG-PON.
  • WDM1 requires high optical signal working band isolation, low optical network insertion loss, practical and cost-effective process implementation methods for existing TDM-PON and NG-PON band planning, and so far, there is no WDM1 device module. How to implement the program.
  • the technical problem to be solved by the present invention is to provide a wavelength division multiplexer compatible with two passive optical networks, which can realize wavelength division multiplexing and demultiplexing functions of optical signals of a base band and an upgrade band.
  • the present invention provides a wavelength division multiplexer compatible with two passive optical networks, which is used to implement compatibility between a next-generation passive optical network and an existing time division multiplexed passive optical network.
  • the sub-band passive optical network sometimes uses a base band
  • the next-generation passive optical network uses an upgrade band
  • the base band and the upgrade band both include an uplink band and a downlink band
  • the wavelength division multiplexer includes an upgraded optical line. Terminal port, legacy optical line terminal port, and public port, where:
  • the wavelength division multiplexer further includes one or more filters for optical signals of a base band input from a legacy optical line terminal port and an upgraded band optical signal input from an upgrade optical line terminal port in a downlink direction. Performing multiplexing to output the obtained wavelength division multiplexed optical signal from the common port; in the uplink direction, demultiplexing the wavelength division multiplexed optical signal input from the common port into the optical signal of the base band and the upgrade band, and The optical signal of the base band is output from the legacy optical line terminal port, and the optical signal of the upgraded band is output from the upgrade optical line terminal port.
  • wavelength division multiplexer may further have the following features, the wavelength division multiplexer includes a plurality of filters, and the following conditions are met:
  • At least one transmission band including the base band from the filter for demultiplexing the two uplink band optical signals to the upgrade optical line terminal port includes the demultiplexing
  • On the upstream optical channel of the filter at least one transmission band includes an upstream band of the upgrade band and the reflection band includes a filter of the uplink band of the base band;
  • At least one transmission band includes a downlink band of the base band and the reflection band includes Upgrade the downstream band of the band;
  • At least one transmission band includes a downlink band of the upgrade band and the reflection band includes The filter of the downstream band of the base band.
  • the wavelength division multiplexer may further have the following features, the wavelength division multiplexer includes a first filter, a second filter, a third filter, and a fourth filter, and is in an upgrade optical line terminal port. Between the common end of the first filter, the reflective end of the first filter and the transmissive or common end of the fourth filter, the common or transmissive end of the fourth filter and the reflective end of the third filter Between the transmitting end of the first filter and the reflecting end of the second filter, between the remaining optical line terminal port and the transmitting end of the second filter, the common end of the second filter and the third filter There is an optical path between the transmissive ends, and between the common port of the wavelength division multiplexer and the common end of the third filter.
  • the wavelength division multiplexer may further have the following characteristics: the first filter is a band pass or a sideband filter, and the transmission band includes a downlink band of an upgrade band, and the reflection band includes an uplink band and a base band of the upgrade band.
  • the second filter is a sideband filter, the transmission band includes an uplink band and a base band of the upgrade band, and the reflection band includes a downlink band of the upgrade band;
  • the third filter is a sideband filter, and the transmission band includes an upgrade.
  • the downlink and base bands of the band, the reflection band includes the upstream band of the upgrade band;
  • the fourth filter is a band pass or a sideband filter, the transmission band includes an up band of the upgrade band, and the reflection band includes a down band of the upgrade band and Base band; or
  • the first filter is a band pass or a sideband filter, and the transmission band includes an uplink band of an upgrade band, and the reflection band includes a downlink band and a base band of the upgrade band;
  • the second filter is a sideband filter, and the transmission band includes an upgrade.
  • the downstream and fundamental bands of the band, including the upgrade band The upstream filter;
  • the third filter is a sideband filter, the transmission filter includes an upstream band and a base band of the upgrade band, the reflection band includes a downlink band of the upgrade band;
  • the fourth filter is a band pass or sideband filter, and the transmission band Includes the downstream band of the upgrade band, which includes the base band and upgrade filtering and upstream bands.
  • the wavelength division multiplexer may further have the following features, the wavelength division multiplexer includes a first filter, a second filter, a third filter, and a fourth filter, and is in an upgrade optical line terminal port. Between the common end of the first filter, between the reflective end of the first filter and the transmissive end of the third filter, between the transmissive end of the first filter and the reflected end of the second filter, the second filtering Between the transmitting end of the device and the transmitting end or the common end of the fourth filter, between the common end of the second filter and the reflecting end of the third filter, the common end of the third filter and the wavelength division multiplexing There is an optical path between the common ports of the device, and the common or transmissive end of the fourth filter and the legacy optical line termination port.
  • the wavelength division multiplexer may further have the following characteristics: the first filter is a band pass or a sideband filter, and the transmission band includes a downlink band of an upgrade band, and the reflection band includes an uplink band and a base band of the upgrade band.
  • the second filter is a sideband filter, the transmission band includes an uplink band and a base band of the upgrade band, and the reflection band includes a downlink band of the upgrade band;
  • the third filter is a band pass or a sideband filter, and the transmission The band includes an upstream band of the upgrade band, and the reflection band includes a downlink band and a base band of the upgrade band;
  • the fourth filter is a sideband filter, and the transmission band includes a downlink band and a base band of the upgrade band, and the reflection band includes an upgrade band.
  • the first filter is a band pass or a sideband filter, the transmission band includes an uplink band of an upgrade band, and the reflection band includes a downlink band and a base band of the upgrade band;
  • the second filter is a sideband filter, a transmission band The downlink band and the base band of the upgrade band are included, and the reflection band includes an uplink band of the upgrade band;
  • the third filter is a band pass or a sideband filter, and the transmission band includes a downlink band of the upgrade band, and the reflection band includes an uplink of the upgrade band.
  • the band and the base band; the fourth filter is a sideband filter, the transmission band includes an uplink band and a base band of the upgrade band, and the reflection band includes a downlink band of the upgrade band.
  • the wavelength division multiplexer may further have the following features, the wavelength division multiplexer includes a first filter, a second filter, a third filter, and a fourth filter, and is in an upgrade optical line terminal port. Between the common end of the first filter, the reflective end of the first filter and the transmitting end of the second filter Or between the common end, between the transmissive end of the first filter and the reflective end of the fourth filter, between the common end or the transmissive end of the second filter and the reflective end of the third filter, the third filter Between the common end and the transmissive end of the fourth filter, between the transmissive end of the third filter and the legacy optical line termination port, and between the common end of the fourth filter and the common port of the wavelength division multiplexer There is a light channel.
  • the wavelength division multiplexer may further have the following characteristics: the first filter is a band pass or a sideband filter, and the transmission band includes an uplink band of an upgrade band, and the reflection band includes a downlink band and a base band of the upgrade band.
  • the second filter is a band pass or a sideband filter, the transmission band includes a downlink band of the upgrade band, and the reflection band includes an uplink band and a base band of the upgrade band;
  • the third filter is band pass or sideband filter
  • the transmission band includes an uplink band and a base band of the upgrade band, and the reflection band includes a downlink band of the upgrade band;
  • the fourth filter is a sideband filter, and the transmission band includes a downlink band and a base band of the upgrade band, and the reflection band includes Upgrade the upstream band of the band; or
  • the first filter is a band pass or a sideband filter, the transmission band includes a downlink band of the upgrade band, and the reflection band includes an uplink band and a base band of the upgrade band;
  • the second filter is a band pass or a side band filter
  • the transmission band includes an uplink band of the upgrade band, and the reflection band includes a downlink band and a base band of the upgrade band;
  • the third filter is a sideband filter, and the transmission band includes a downlink band and a base band of the upgrade band, and the reflection band includes an upgrade.
  • the uplink band of the band; the fourth filter is a sideband filter, the transmission band includes an uplink band and a base band of the upgrade band, and the reflection band includes a downlink band of the upgrade band.
  • the wavelength division multiplexer may further have the following feature, the wavelength division multiplexer includes a band pass filter, a transmissive end of the band pass filter and a legacy optical line terminal port, a common end and the An optical channel between the common ports of the wavelength division multiplexer and the reflective end and the upgrade optical line terminal port; and the transmission band of the band pass filter includes a base band, and the reflection band includes an upgrade band; or
  • the transmission band of the bandpass filter includes an upgrade band
  • the reflection band includes the base band
  • the wavelength division multiplexer may further have the following characteristics: the filter configuration in the wavelength division multiplexer and its spectral characteristics are one of the following ways: First, the wavelength division multiplexer includes a first filter, a second filter, and a third filter.
  • the transmission band of the first filter includes a downlink band of the upgrade band, and the reflection band includes an uplink band of the upgrade band and The base band;
  • the transmission band of the second filter includes the upstream band of the upgrade band, the reflection band includes the downlink band and the base band of the upgrade band;
  • the transmission band of the third filter includes the base band, and the reflection band includes the upgrade band;
  • first filter and the second filter position in the first mode are interchanged, and the optical properties of each filter are the same as the first mode;
  • the wavelength division multiplexer includes a first filter and a second filter, wherein a transmission band of the first filter includes a base band, and a reflection band includes an upgrade band; and a transmission band of the second filter includes an upgrade band,
  • the reflection band includes a base band; between the connection, the legacy optical line terminal port and the transmission end of the first filter, between the common port of the wavelength division multiplexer and the common end of the first filter, the optical line terminal is upgraded
  • An optical path exists between the port and the transmissive or common end of the second filter, and between the common or transmissive end of the second filter and the reflective end of the first filter;
  • the wavelength division multiplexer comprises a first filter and a second filter
  • the first filtered transmission band comprises an upgrade band
  • the reflection band comprises a base band slice
  • the transmission band of the second filter comprises a base band
  • the reflection band includes an upgrade band; the connection, between the transmission end of the first filter and the upgrade optical line terminal port, between the reflection end of the first filter and the transmission end or the common end of the second filter, the first filter a light path exists between the common end and the common end of the wavelength division multiplexer, and between the common or transmissive end of the second filter and the legacy optical line terminal port;
  • the wavelength division multiplexer includes a first filter, a second filter, and a third filter
  • the transmission band of the first filter includes an upgrade band
  • the reflection band includes a base band
  • the transmission of the second filter The band includes an upstream band and a base band of the upgrade band
  • the reflection band includes a downlink band of the upgrade band
  • the transmission band of the third filter includes a downlink band and a base band of the upgrade band
  • the reflection band includes an uplink band of the upgrade band
  • the second filter and the third filter position in the fifth mode are interchanged, and the optical language characteristics of each filter are the same as the fifth mode.
  • the wavelength division multiplexer may further have the following feature, wherein the filters in the wavelength division multiplexer are all thin film filters.
  • wavelength division multiplexer may further have the following features, and is characterized by:
  • the uplink band of the upgrade band is in the range of 1260 nm to 1280 nm, and the downlink band of the upgrade band is in the 1550 nm to 1580 nm band; the upstream band of the base band is in the range of 1290 nm to 1330 ⁇ band, that is, the O band, the basis
  • the downstream band of the band is 1480 nm to 1500 nm, which is the S band.
  • the WDM1 provided by the invention realizes the wavelength division multiplexing and demultiplexing functions of the optical signals of the base band and the upgrade band.
  • the optical distribution network of the existing time division multiplexed passive optical network can simultaneously transmit the next generation passive optical network, realize the smooth evolution of TDM-PON to NG-PON, and provide subsequent network compatibility for the deployed TDM-PON system. .
  • the high isolation requirement of the optical signal operating band can be satisfied at a lower cost, and the number of the filter and its light can be appropriately set.
  • the language characteristics can also take into account the isolation and the requirements for optical network insertion loss.
  • the WDM1 is realized by a simple and practical technology, and the cost is low, the reliability is high, and the use and system upgrade are convenient.
  • FIG. 1 is a schematic structural diagram of an external interface of a WDM 1 according to an embodiment of the present invention
  • Figure 2 (a) is a schematic structural view of the WDM 1 according to the first embodiment of the present invention, showing the optical transmission paths in the upstream and downstream directions;
  • Figure 2 (b) - Figure 2 (1) is the first embodiment and its transformation a schematic diagram of the spectrum of each filter in the mode;
  • Figure 3 (a) is a schematic structural view of a WDM 1 according to a second embodiment of the present invention
  • Figure 3 (b) - Figure 3 (d) is a schematic diagram of the spectra of the respective filters in the second embodiment
  • FIG. 4(a) is a schematic structural view of a WDM1 according to a third embodiment of the present invention
  • FIG. 4(b) is a schematic view showing the spectrum of the filter in the third embodiment
  • Figure 5 (a) is a schematic structural view of a WDM 1 according to a fourth embodiment of the present invention
  • Figure 5 (b) is a schematic view showing the optical language of the filter in the fourth embodiment
  • FIGS. 6(a) is a schematic structural view of a WDM1 according to a fifth embodiment of the present invention
  • FIGS. 6(b) to 6(c) are schematic diagrams showing spectra of respective filters in the fifth embodiment
  • Figure 7 (a) is a schematic structural view of a WDM 1 according to a sixth embodiment of the present invention.
  • (c) is a schematic diagram of the spectrum of each of the filters in the sixth embodiment.
  • Figure 8 (a) is a schematic structural view of a WDM 1 according to a seventh embodiment of the present invention.
  • (d) is a schematic diagram of the optical language of each filter in the seventh embodiment
  • FIGS. 9(a) is a schematic structural view of a WDM1 according to an eighth embodiment of the present invention.
  • FIGS. 9(b) to 9(d) are schematic diagrams showing the optical language of each filter in the eighth embodiment;
  • Figure 10 (a) is a schematic structural view of a WDM 1 according to a ninth embodiment of the present invention
  • Figure 10 (b) - Figure 10 (d) is a schematic diagram of the optical language of each filter in the ninth embodiment
  • Figure 11 (a) is a schematic structural view of a WDM 1 according to a tenth embodiment of the present invention
  • Figure 11 (b) to Figure 11 (i) are schematic diagrams showing the optical language of each filter in the tenth embodiment and its conversion mode
  • FIG. 12(a) is a schematic structural view of a WDM1 according to an eleventh embodiment of the present invention
  • FIG. 12(b) to FIG. 12(e) are schematic diagrams showing spectra of respective filters in the eleventh embodiment
  • Figure 13 is a diagram showing the network structure of the WDM1 implementing the NG-PON compatible G-PON according to the embodiment of the present invention.
  • the upgrade band in this paper includes the upstream band and the downlink band, and the upstream band is 1260 nm to 1280.
  • the ⁇ band, the downstream band is 1550 ⁇ to 1580 ⁇ band, including the 1550 ⁇ to 1560 nm band and the 1575 nm to 1580 nm band.
  • the base band also includes the upstream band and the downlink band, and the uplink band is 1290 ⁇ to 1330 ⁇ band, that is, the O band, and the downlink band is 1480 nm to 1500 ⁇ band, that is, the S band. It should be noted that the above-mentioned wavelength plan may also be changed. As long as the distribution relationship of the above four bands is unchanged, the WDM1 of the present invention is also applicable.
  • the wavelength division multiplexer is used as an access point for optical signals of different wavelengths, and needs to meet the following requirements:
  • the wavelength division multiplexing optical signal of the NG-PON and the optical signal of the existing TDM-PON are implemented by wavelength division multiplexing and demultiplexing on the existing optical distribution network;
  • thin film filters are more suitable for wideband filtering and have a mature fabrication process that can be used in WDM1.
  • the thin film filter has the function of transmission and reflection, and the corresponding working band can be called the transmission band and the reflection band.
  • the isolation at the transmission end is very good, and it is not easy to be crosstalked by optical signals in other bands, and the isolation can reach 35dB.
  • the isolation of the reflection end is relatively poor, 15dB, and the optical signal in the transmission band can be crosstalked to the reflection end, and it is necessary to take reinforcement measures.
  • the insertion loss is proportional to the number of thin film filters. Therefore, the minimum number of filters is preferred when isolation is guaranteed.
  • the embodiments hereinafter are all implemented by a thin film filter, and the present invention does not limit the type of filter used, and can be applied to the WDM 1 of the present invention as long as the same spectral characteristics can be attained.
  • the central office places the legacy optical line terminal and the upgraded optical line terminal, and the external interface of the WDM1 is as shown in FIG. 1 , including the legacy optical line.
  • Terminal port, upgrade optical line terminal port and public port mouth :
  • the optical signal of the base band is input to the terminal port of the legacy optical line
  • the optical signal of the upgrade band is input to the terminal port of the upgraded optical line
  • the wavelength division multiplexer inputs the optical signal of the input baseband and the optical signal of the upgraded band.
  • it is output from the common port, so that the optical signals of the two bands are transmitted in a single optical fiber, and then finally transmitted to the respective ONU devices through optical devices such as optical splitters;
  • the two bands of wavelength division multiplexed light The signal is input from the common port of the WDM1 by using the same fiber.
  • the WDM1 transmits the optical signals of the base band and the upgrade band to the legacy optical line terminal port and the upgrade optical line terminal port.
  • the total bandwidth of the base band is 210 nm (the range of the downstream S-band is 1480 nm to 1500 nm, and the range of the upstream O-band is 1290 nm to 1330 nm).
  • the upstream and downstream bands of the upgrade band are distributed on both sides of the base band (upstream The band is between 1260 nm and 1280 nm, and the downstream band is between 1550 nm and 1580 nm.
  • the downstream band here consists of two parts, the CATV downlink band and the NG-PON downlink band.
  • the interval between the upstream band of the base band and the upstream band of the upgrade band is narrower by about 10 nm. Therefore, the bandwidth of the base band is relatively large, and the band spacing between the two bands is relatively small.
  • WDM1 Due to the requirements of WDM1 preparation process and telecom network application requirements and cost, combined with the characteristics of the above basic band and upgrade band, WDM1 can be assembled by using sideband filter and/or bandpass filter.
  • the WDM 1 includes four thin film filters, namely a band pass filter fl l and a side band filter fl 2 .
  • the sideband or bandpass filters can be three-terminal devices, including the transmissive end, the reflective end, and the common end.
  • Some bandpass or sideband filters such as fl4 can also be two-terminal devices, including the transmissive end and the common end.
  • the reflective end and the common end are on the same side of the filter.
  • the transmissive end is on the other side.
  • the arrow on the line opposite the transmission end is opposite (refers to or away from the filter) as the reflection end.
  • the transmission band of the bandpass filter fl l includes 1550 ⁇ to 1580 ⁇ , and the reflection band includes 1260 ⁇ to 1500 ⁇ ; the transmission band of the sideband filter fl2 includes 1260 ⁇ to 1500 ⁇ , and 1550 ⁇ to 1580 ⁇ is located on the reflection band thereof.
  • 1290 ⁇ to 1580 ⁇ is in the transmission band of the sideband filter fl3, 1260 nm to 1280 nm is in the reflection band of fl3; 1260 nm to 1280 nm is in the transmission band of the bandpass filter fl4, 1290 ⁇ to 1580 ⁇ is located in fl4 Reflected band.
  • the band pass filter Between the common end of fl4 and the reflection end of the sideband filter fi3, between the transmission end of the band pass filter fl l and the reflection end of the sideband filter fl2, the transmission of the legacy optical line terminal port and the sideband filter fl2 Between the ends, between the common end of the sideband filter fl2 and the transmitting end of the sideband filter fl3, there is an optical channel between the WDM1 common port and the common end of the sideband filter fl3.
  • fl4 The common and transmissive ends of fl4 are interchangeable.
  • some optical channels are represented by fold lines. In actual devices, the optical channels are as straight as possible, but it is not excluded that the transmission direction of the optical signals of one optical channel changes by adding reflective means. happening. Other embodiments are the same.
  • the arrow in the figure is an example of the downward direction, and the direction of all the arrows is reversed in the upward direction.
  • the downstream signal of NG-PON (wavelength is 1550 ⁇ to 1580 nm) is incident from the upgraded optical line terminal port of WDM1, enters the common end of the bandpass filter fl l, and passes through the transmission of the bandpass filter fl l After entering the sideband filter fl2 and reflecting through it, it enters the transmission end of the sideband filter A3, and after transmission, is output to the common port of the WDM1 by the common end of the sideband filter fl3; meanwhile, the downstream wavelength of the G-PON ( The wavelength range is from 1480 ⁇ to 1500 ⁇ ).
  • the signals output from the common port of the WDM1 are the downlink signals of the NG-PON and the wavelength division multiplexed signals of the downlink signals of the G-PON.
  • the WDM signal input from the WDM1 common port includes the upstream signal of the NG-PON (upstream band from 1260 nm to 1280 nm) and the G-PON uplink signal (band) At 1290 nm to 1330 nm), the upstream signal of the NG-PON enters the common end of the sideband filter fl3 after being incident on the common port of the WDM1, and is reflected by the sideband filter fl3 and enters the common end of the bandpass filter fl4. After being transmitted by fl4, it is output from the transmissive end of fl4 to the reflection end of the band-pass filter fl l.
  • the uplink signal of G-PON is from
  • the common port of the WDM1 is outputted by the transmitting end and enters the common end of the sideband filter fl2, and is transmitted from the transmitting end to the residual light of the WDM1 by the sideband filter fl2.
  • Line termination port Complete understanding of reuse.
  • the WDM1 device of the present embodiment can achieve the high isolation between the upgrade band and the base band while realizing wavelength division multiplexing and demultiplexing. What needs to be considered is the crosstalk between the upstream band of the upgrade band and the upstream band of the base band, and the downlink band of the base band and the downlink band of the upgrade band.
  • the isolation of the transmission end of the filter is high, if the filter is demultiplexed from the two upstream optical signals to the upstream optical channel of the legacy optical line terminal port of WDM1 (including the demultiplexed filter) At least one transmission band containing the upstream band of the base band and the reflection band containing the upstream band of the upgrade band, from the filter that demultiplexes the two upstream band optical signals to the upgraded optical line terminal port of WDM1 (including The filter of the upstream band of the upstream optical channel segment of the demultiplexed filter) can achieve the isolation requirement between the two upstream bands by using a common filter. If there is at least one transmission band from the legacy optical line termination port of WDM1 to the downstream optical channel of the filter (including the multiplexed filter) that multiplexes the two downlink optical signals
  • the upgrade optical line terminal port of WDM1 to the downstream optical channel of the filter (including the multiplexed filter) for multiplexing the two downlink optical signals includes at least one transmission band including the downlink band of the upgrade band and the reflection band includes the basis.
  • the filter of the downstream band of the band can achieve the isolation requirement between the two downstream bands.
  • the above four conditions are collectively referred to as a first isolation condition.
  • the filter that can satisfy the requirement is that the filter that demultiplexes the two uplink optical signals is fl3, and the filter that passes from the fl3 to the upstream optical channel of the legacy optical line terminal port includes fl3, and fl2, the basic band.
  • the upstream band is located in the transmission band of fl3 and the upstream band of the upgrade band is located in the reflection band of A3.
  • Filter package from f!3 to the upstream optical channel of the upgrade optical line terminal port Including fl3, fl4 and fl l, wherein the uplink band of the upgrade band is located in the transmission band of fl4 and the uplink band of the base band is located in the reflection band of fl4.
  • the filter that multiplexes the two downlink optical signals is fl2 (the two signals are separated when the two signals are multiplexed into the filter, and the two signals are combined when outputting), from the residual light
  • the filter passing through the line end port to the downstream optical channel of fl2 is fl2, the transmission band of fl2 includes the downlink band of the base band, and the reflection band includes the downlink band of the upgrade band, and the downlink optical channel from the upgrade optical line terminal port to the fl2 passes.
  • the filter includes fl l and fl2, and the transmission band of fl l includes the downlink band of the upgrade band and the reflection band includes the downlink band of the base band.
  • the isolation between the two uplink bands and between the two downlink bands can be ensured, and all the filters can be implemented by using ordinary filters, thereby reducing the cost of the WDM1.
  • Transformation mode 1 the structure diagram is still shown in Figure 2 (a), the spectrum diagram is shown in Figure 2 (f) ⁇ Figure 2 (1), the bandpass filter fl l is changed to the sideband filter, 1550nm to 1580nm Located in its transmission band, 1260nm to 1500nm is in its reflection band, bandpass filter fl4 is changed to sideband filter, 1260nm to 1280nm is in its transmission band, and 1290nm to 1580nm is in its reflection band.
  • the sideband filters fl2 and fl3 have the same type and spectral characteristics.
  • the transmission and reflection relationships of the upper and lower bands of the fundamental band and the upper and lower bands of the upgrade band (also referred to as the four bands of WDM1) are unchanged, so the performance is basically identical.
  • the above fl 1 and fl4 can also change only one of them.
  • fl l ⁇ fl4 are sideband filters, and the spectral characteristics are as follows:
  • the transmission band of the sideband filter fl l includes 1260 nm to 1280 nm, and the reflection band includes 1290 nm to 1580 nm;
  • the sideband filter fl2 has a transmission band of 1290 nm to 1580 nm, and the reflection band includes 1260 ⁇ to 1280 ⁇ ;
  • the sideband filter fl3 has a transmission band of 1260 ⁇ to 1500 nm, and the reflection band includes 1550 ⁇ .
  • the sideband filter fl4 has a transmission band of 1550 ⁇ to 1580 ⁇ and a reflection band of 1260 ⁇ to 1500 ⁇ .
  • the sideband filter fl l and/or the sideband filter fl4 are changed to bandpass filters, and are related in the optical properties of the bandpass filters fl l and fl4
  • the transmission or reflection relationship of the four bands is the same as fl l and fl4 in the second mode.
  • the WDM 1 of this embodiment includes three thin film filters, which are a sideband filter £21, a sideband filter £22, and a bandpass filter £23.
  • Figures 3(b) to 3(d) show the spectra of the respective filters.
  • 1550 nm to 1580 nm is located in the transmission band of the sideband filter £21, 1260 nm to 1500 nm in the reflection band; 1260 nm to 1280 nm is located in the transmission of the sideband filter £22
  • the band, 1290 ⁇ to 1580 ⁇ is located in its reflection band; the 1290 ⁇ to 1500 nm is located in the transmission band of the bandpass filter £23, the 1260 ⁇ to 1280 ⁇ band and the 1550 ⁇ to 1580 nm band are located in the reflection band of 3.
  • the downstream signal of NG-PON (band 1550-1580 ⁇ ) is incident from the upgraded optical line termination port of WDM1, enters the common side of the sideband filter £21, and passes through the sideband filter £21.
  • the side end of the sideband filter £22 is reflected by the sideband filter £22 and output from its common terminal to the reflection end of the bandpass filter £23.
  • the common side of the bandpass filter £23 Output to the common port of WDM1; meanwhile, the downstream signal of G-PON (band 1480 nm to 1500 nm) is incident from the terminal port of the legacy optical line of the WDM 1 and enters the transmission end of the bandpass filter £3.
  • the transmission of the filter £23 is output from its common terminal to the common port of WDM1, so the signal output from the common port of WDM1 is the downstream signal of NG-PON and the wavelength division multiplexed signal of the downstream signal of G-PON.
  • the wavelength division multiplexed signal input from the WDM1 common port includes an uplink signal of the NG-PON and an uplink signal of the G-PON, wherein the uplink signal of the NG-PON enters the bandpass filter after being incident from the common port of the WDM1.
  • the common end of £23 is reflected by the bandpass filter and reflected by its reflection end and then enters the common end of the sideband filter £22. After transmission, it is output to the sideband filter by the transmission end of the sideband filter £22.
  • the reflection end of £21 is reflected by the sideband filter and is output from its common terminal to the upgraded optical line terminal port of WDM1.
  • the G-PON uplink signal enters the bandpass filter from the common port of WDM1.
  • the common end of £3, transmitted through the bandpass filter £3, is output by the bandpass filter £23 transmission end to the legacy optical line termination port of WDM1.
  • this embodiment also satisfies the above first isolation condition. Since the manufacturing process difficulty of the thin film filter is proportional to the band width and isolation of the filter, it is inversely proportional to the protection bandwidth interval.
  • the sideband filter £21 and the sideband filter £22 enhance the isolation of the reflection direction, indirectly reducing the isolation of the bandpass filter's £23 reflection direction, thereby reducing the thin film filtering.
  • the process preparation difficulty of the device can make the number of coating layers of the thin film filter lower and the processing difficulty is reduced, as is the case for each filter in the first embodiment.
  • the band pass filter of the present embodiment has a relatively large band pass width, and it is difficult to realize the filter of the first embodiment.
  • the WDM1 of the first embodiment is relatively inexpensive.
  • the band-pass filter ⁇ can be directly used to achieve the above-mentioned wavelength division multiplexing/demultiplexing function, that is, the band-pass film filter is used to form the WDM1 with broadband high isolation.
  • the wavelength division multiplexing/demultiplexing function of the band and the upgrade band and the high isolation requirement the schematic diagram of the uplink and downlink working principle of the WDM1 is shown in Fig. 4 (a), the transmission end of the ⁇ and the WDM1 legacy optical line terminal port. Between the common end of ⁇ 1 and the common port of WDM1, there is an optical path between the reflective end of ⁇ 1 and the upgrade optical line termination port of WDM1.
  • Figure 4 (b) is a schematic diagram of the optical ⁇ of ⁇ , in which the 1290 ⁇ to 1500 ⁇ band is located in the transmission band of ⁇ , and the 1260 ⁇ to 1280 ⁇ band and the 1550 ⁇ to 1580 ⁇ band are located in the reflection band of ⁇ .
  • the band pass filter ⁇ Through the band pass filter ⁇ , the multiplexing and demultiplexing of the base band and the upgrade band optical signals can be directly realized.
  • a bandpass filter ⁇ is used to implement the above-mentioned wavelength division multiplexing/demultiplexing function, and a plurality of slices of ⁇ can be assembled to realize the above-described wavelength division multiplexing/demultiplexing function.
  • the WDM1 of this embodiment only one band pass filter f41 is used, as shown in FIG. 5(a), the transmitting end of the f41 and the upgrade optical line terminal port of the WDM1, the common end of the f41 and the WDM1. Between the common ports, there is an optical path between the reflective end of f41 and the legacy optical line termination port of WDM1.
  • Figure 5 (b) is a schematic diagram of the optical language of f41, in which the 1290 ⁇ to 1500 ⁇ band is located in the reflection band of f41, the 1260 ⁇ to 1280 ⁇ band and the 1550 ⁇ to 1580 ⁇ band are located in the transmission band of f41.
  • the band pass filter f41 Through the band pass filter f41, the multiplexing and demultiplexing of the base band and the upgrade band optical signals can be directly realized.
  • the WDM 1 of the present embodiment includes a band pass filter f51 and a band pass filter f52.
  • the 1290 ⁇ to 1500 ⁇ band is located in the transmission band of f51, and the 1260 ⁇ to 1280 ⁇ band and the 1550 ⁇ to 1580 ⁇ band are located in the reflection band of f51.
  • the 1290 ⁇ to 1500 ⁇ band is located in the reflection band of f52, and the 1260 ⁇ to 1280 ⁇ band and 1550 ⁇ to 1580 ⁇ band are located in the transmission band of f52.
  • the first isolation condition has a small insertion loss.
  • the WDM1 of this embodiment includes band pass filters f61 and f62, wherein the spectral characteristics of f61 are the same as f52 in the fifth embodiment, and the optical language characteristics of f62 and the fifth embodiment are as shown in FIG. The same is true for f51.
  • connection relationship between the filters and the port of the filter and the WDM1 is changed, wherein the transmission end of the band pass filter f61 and the upgrade optical line terminal port of the WDM1, the reflection end of the f61 and the f62 Between the transmissive ends, there is an optical path between the common end of f61 and the common end of WDM1, the common end of f62 and the legacy optical line termination port of WDM1.
  • the common and transmissive ends of f62 are interchangeable.
  • the WDM1 of the present embodiment can also implement multiplexing and demultiplexing of the upgrade band and the base band optical signal, and also satisfy the above first isolation condition, and the insertion loss is small.
  • the structure of the WDM 1 of this embodiment is as shown in Fig. 8 (a), and includes a sideband filter ⁇ 1, a sideband filter ⁇ 2, and a band pass filter ⁇ 3.
  • the spectral characteristics of each filter are shown in Fig. 8 (b) ⁇ (d). It can be seen that this embodiment is basically the same as the structure of the second embodiment, and is equivalent to the positional switching of the sideband filters f51 and f52 in the second embodiment, and the performance is not affected. Detailed descriptions are not repeated here.
  • the WDM1 of the present embodiment includes a band pass filter f81, a sideband filter f82, and a sideband filter f83.
  • the transmission band of f82 includes 1260 nm to 1500 nm
  • the reflection segment includes 1550 nm to 1580 ⁇
  • the transmission band of f83 includes 1290 ⁇ to 1580 ⁇
  • the reflection segment includes 1260 ⁇ to 1280 ⁇ .
  • the optical language characteristics of the f81 of the present embodiment and the f61 of the sixth embodiment are the same, and the two side-by-side sideband filters f82 and f83 function substantially the same as f62, and the superposed optical language characteristics are also the same as f62. . Only the sideband filters f82 and f83 are easier to implement. Therefore, the WDM 1 of the present embodiment can also implement multiplexing and demultiplexing of the upgrade band and the base band optical signal, and also satisfy the above first isolation condition.
  • This embodiment only interchanges the positions of the sideband filter f82 and the sideband filter f83 in the eighth embodiment, and will not be described in detail herein.
  • the WDM1 of the present embodiment includes sideband filters fl01, fl02, fl03, and f!04.
  • the sideband filter flOl has a transmission band of 1550 nm to 1580 ⁇ , and the reflection band includes 1260 ⁇ to 1500 ⁇ ; the sideband filter fl02 has a transmission band of 1260 ⁇ to 1500 ⁇ .
  • the reflection band includes 1550 ⁇ to 1580 ⁇ ; the sideband filter fl03 has a transmission band of 1260 ⁇ to 1280 ⁇ , and the reflection band includes 1290 ⁇ to 1580 ⁇ ; the sideband filter fl04 has a transmission band of 1290 ⁇ to 1580 ⁇ , reflection
  • the band contains 1260 nm to 1280 ⁇ .
  • the WDM1 of the embodiment can implement the upgrade band. And wavelength division multiplexing and demultiplexing of the optical signal of the base band, and also satisfying the first isolation condition described above.
  • the filters used in this embodiment are all sideband filters, and the cost is low.
  • This embodiment also has some transformations by varying the type and/or spectral characteristics of the filter, such as:
  • Transformation mode 1 the structure diagram is still shown in Figure 11 (a), the connection relationship of each filter fl01 ⁇ fl04 is unchanged, the sideband filter flOl is changed to the transmission band containing 1550nm to 1580nm, and the reflection band is 1260nm to 1500nm.
  • the band pass filter changes the sideband filter fl03 to a transmission band of 1260 nm to 1280 nm, the reflection band includes a bandpass filter of 1290 nm to 1580 nm, and the sideband filters fl02 and fl04 are unchanged.
  • the transformed WDM1 is identical to the performance of WDM1 before the transformation. It is also possible to change only one of flOl and fl03.
  • the structure diagram is still as shown in Fig. 11 (a), the connection relationship of each filter fl01 ⁇ fl04 is unchanged, and the optical language features of each sideband filter are changed as shown in Fig. 11 (f) ⁇
  • the sideband filter flOl has a transmission band of 1260 ⁇ to 1280 ⁇ , and the reflection band includes 1290 nm to 1580 nm
  • the sideband filter fl02 has a transmission band of 1290 nm to 1580 nm, and the reflection band includes 1260 ⁇ to 1280 ⁇
  • the transmission band with filter fl03 includes 1550 ⁇ to 1580nm
  • the reflection band includes 1260nm to 1500nm.
  • the transmission band of sideband filter fl04 includes 1260nm to 1500 ⁇ , and the reflection band includes 1550 ⁇ to 1580 ⁇ .
  • WDM1 can also implement multiplexing and demultiplexing of optical signals in the upgrade band and the base band, and still satisfy the above first isolation condition.
  • the sideband filter flOl is changed to a transmission band containing 1260 nm to 1280 nm, and the reflection band includes a bandpass filter of 1290 nm to 1580 nm; and/or, the sideband filter fl03 can be
  • the transmission band includes 1550 nm to 1580 nm, and the reflection band includes 1260 nm to 1500 nm band-pass filters.
  • the structure of the WDM 1 of this embodiment is as shown in FIG. 12( a ), and includes a band pass filter fl ll , a band pass filter fl l2 , a sideband filter fl l3 , and a sideband filter fl l4 .
  • the phonological characteristics are shown in Fig. 12 (b) -12 (e).
  • the transmission band of the bandpass filter fi ll includes 1260 nm to 1280 nm, and the reflected wave
  • the segment includes 1290nm to 1580nm;
  • the transmission band of the bandpass filter fll2 includes 1550 ⁇ to 1580 ⁇ , and the reflection band includes 1260 ⁇ to 1500 ⁇ ;
  • the transmission band of the sideband filter fll3 includes 1260 ⁇ to 1500 ⁇ , and the reflection band includes 1550 ⁇ .
  • the transmission band of the sideband filter fll4 includes 1290 ⁇ to 1580 ⁇ , and the reflection band includes 1260 ⁇ to 1280 ⁇ .
  • connection relationship between the upgrade optical line terminal port of WDM1 and the common end of the band pass filter fl11, between the transmission end of fill and the reflection end of fll4, the reflection end of fill and the transmission end (or common end) of fll2 Between the common end of fll2 (or the transmitting end) and the reflective end of fll3, between the transmitting end of fll3 and the terminal line of the legacy optical line, between the common end of fll3 and the transmitting end of fll4, the common end of fll4 There is an optical channel between the common ports of WDM1.
  • This embodiment also has some transformations by varying the type and/or spectral characteristics of the filter, such as:
  • the connection relationship of flll ⁇ fll4 is still as shown in Fig. 12(a), but the bandpass filter fill is changed to the sideband filter, the transmission band includes 1260 ⁇ to 1280 ⁇ , and the reflection band includes 1290nm to 1580nm; And/or, the bandpass filter fll2 is changed to a sideband filter, the transmission band includes 1550 ⁇ to 1580 ⁇ , and the reflection band includes 1260 ⁇ to 1500 ⁇ .
  • the sideband filters fll3 and fll4 have the same type and spectral characteristics.
  • connection relationship of flll ⁇ fll4 is still as shown in Fig. 12(a), and fill is still a bandpass filter, but the transmission band includes 1550 ⁇ to 1580 ⁇ , and the reflection band includes 1260 ⁇ to 1500 ⁇ ; fll2 is still Bandpass filter, but the transmission band includes 1260 ⁇ to 1280 ⁇ , the reflection band includes 1290nm to 1580nm; fl 13 is still a sideband filter, but the transmission band includes 1290nm to 1580nm, the reflection band includes 1260nm to 1280nm; fll4 is still edge With filter, but the transmission band includes 1260 ⁇ to 1500 ⁇ , and the reflection band includes 1550 ⁇ to 1580 ⁇ .
  • the bandpass filter fill and/or fl 12 is changed to the sideband filter, and the modified sideband filter fill and fll2 spectral characteristics are related to the transmission of the four bands. Or the reflection relationship is the same as fill and fll2 in the second transformation mode.
  • the WDM1 of this embodiment and all its transformation modes can also realize the light of the upgrade band and the base band.
  • the signal is multiplexed and demultiplexed, and satisfies the above first isolation condition.
  • the G-PON network is taken as an example to describe the implementation of the wavelength division multiplexer according to the embodiment of the present invention.
  • the NG-PON compatible G-PON network structure includes a current G-PON system network architecture based on a baseband band and a next-generation NG-PON system network architecture based on an upgraded band, wherein the G-PON system network architecture includes a G-PON OLT, WDM1, optical splitter and G-PON ONU; Next-generation NG-PON system network architecture includes NG-PON OLT, CATV, WDM1, optical splitter and NG-PON ONU, where smooth upgrade of TDM-PON to NG-PON is required Introduce WDM1 to achieve network compatibility through multiplexing/demultiplexing.
  • the optical signal of the downlink wavelength with a center wavelength of 1490 nm ⁇ 10 nm is transmitted from the G-PON OLT side by the Tx optical module through the filter Filter 1 and then from the legacy optical line terminal port of the WDM1. Then, the common port multiplexed output of the WDM1 is sent to the G-PON ONU through the optical splitter, and finally filtered by the filter Filter 3 in the matching G-PON ONU, and finally received by the Rx; the uplink direction is the same;
  • the optical signal of the downstream wavelength of 1575 nm to 1580 nm is transmitted from the NG-PON OLT side by the Tx optical module through the filter Filter 2, and then the CATV downlink signal with the wavelength of 1550 nm to 1560 nm is passed.
  • a WDM device combines the combined signals (including the 1575 ⁇ to 1580 ⁇ downstream signal of NG-PON and the 1550 ⁇ to 1560nm downlink signal of CATV) and is then input by the WDM1 upgrade optical line terminal port, and then by WDM1.
  • the common port multiplexed output is sent to the NG-PON ONU via the optical splitter, and then filtered by the filter Filter 4 in the matched NG-PON ONU to be received by the Rx.
  • the upward direction is the same, and it will not be described here.
  • the wavelength division multiplexer provided by the invention realizes the wavelength division multiplexing and demultiplexing functions of the optical signals of the base band and the upgrade band.
  • the optical distribution network of the existing time division multiplexed passive optical network can simultaneously transmit the next generation passive optical network, realize the smooth evolution of the existing TDM-PON to the NG-PON, and provide a follow-up to the deployed TDM-PON system. Network compatible.
  • the high isolation requirement of the optical signal operating band can be satisfied at a lower cost, and the number of the filter is appropriately set and
  • the optical language characteristics can also balance the isolation and the insertion loss of the optical network.
  • WDM1 is realized by a simple and practical technology, and the cost is low, the reliability is high, and the use and system upgrade are convenient.

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Description

一种兼容两种无源光网络的波分复用器
技术领域
本发明涉及光接入网通讯领域中时分复用 （ Time Division Multiplexing , TDM )和波分复用 （Wavelength Division Multiplexing, WDM )技术相结合的 下一代无源光网络（ Next Generation - Passive Optical Network , NG-PON ) , 尤其涉及一种用于实现现有时分复用无源光网络（ Time Division Multiplexing - Passive Optical Network , TDM-PON , 包括 ATM-PON、 Broadband-PON、 Ethernet-PON, Gigabit-PON )升级到或兼容下一代无源光网络的波分复用器。
背景技术
光接入网由目前的基于时分复用技术的宽带无源光网络 （ Broadband Passive Optical Network, B-PON )、吉比特无源光网络 ( Gigabit Passive Optical Network , G-PON ) 、 以太网无源光网络 ( Ethernet Passive Optical Network , E-PON )等逐渐向基于时分复用与波分复用技术相结合的多波长及高速率的 下一代无源光网络演化。 在光线路终端（Optical Line Terminal, OLT )和光网 络单元（Optical Network Unit, ONU )之间通过多波长单根光纤的双向高速 传输， 极大提高光纤的利用率。 S波段 的范围在 1480匪至 1500匪，为了与 NG-PON共存，上行 O波段 。 的范围在 1290 nm至 1330 nm。国际电信联盟标准组织 ITU-T光接入网 G.984.5 标准中提及， 现有时分复用无源光网络的光线路终端称为遗留光线路终端 ( Legacy OLT ) , 其工作波段为基础波段 。 下一代无源光网络光线路终 端称为升级光线路终端（ Upgrade OLT )。 全服务接入网 ( Full Service Access Networks, FSAN )组织规划了下一代无源光网络的波长， 上行波长的范围在 1260 nm至 1280 nm,下行波长的范围在 1575 nm至 1580 nm,并规划了 CATV 的下行信号的波长范围在 1550nm至 1560nm。
为了解决 TDM-PON平滑升级或兼容 NG-PON系统的架构， 则必须在遗 留光线路终端、 升级光线路终端与分光器 （ Splitter ) 之间插入 WDM1 ( Wavelength Division Multiplexingl , WDM1 , 在 G.984.5中规定： 用于实现 下一代无源光网络与现有时分复用无源光网络兼容的波分复用器的名称为 WDM1 ) , 使现有 TDM-PON 和 NG-PON 在同一个光分配网 （Optical Distribution Network, ODN )上单纤传输不同波段的光信号， 如图 1 所示。 WDM1能够使现有 TDM-PON的光分配网能够同时传送 NG-PON的光信号， 实现 TDM-PON向 NG-PON的平滑升级。
由于 WDM1对于现有 TDM-PON和 NG-PON波段规划中需要高的光信 号工作波段隔离度， 低的光网络插入损耗， 实用可行性价比高的工艺实现方 法等， 而至今尚未有关于 WDM1器件模块如何实现的方案。
发明内容
本发明要解决的技术问题是提供一种兼容两种无源光网络的波分复用 器， 能够实现基础波段与升级波段的光信号的波分复用和解复用功能。
为了解决上述问题， 本发明提供了一种兼容两种无源光网络的波分复用 器， 用于实现下一代无源光网络与现有时分复用无源光网络的兼容， 所述现 有时分复用无源光网络使用基础波段，所述下一代无源光网络使用升级波段， 所述基础波段和升级波段均包括上行波段和下行波段， 所述波分复用器包括 升级光线路终端端口、 遗留光线路终端端口和公共端口， 其中：
所述波分复用器还包括一个或多个滤波器， 用于在下行方向， 将从遗留 光线路终端端口输入的基础波段的光信号和从升级光线路终端端口输入的升 级波段的光信号进行复用， 将得到的波分复用的光信号从公共端口输出； 在 上行方向， 将从公共端口输入的波分复用的光信号解复用为基础波段和升级 波段的光信号， 并将基础波段的光信号从遗留光线路终端端口输出， 将升级 波段的光信号从升级光线路终端端口输出。
进一步地， 上述波分复用器还可具有以下特点， 该波分复用器包括多个 滤波器， 且满足以下条件：
从将所述两个上行波段光信号解复用的滤波器到遗留光线路终端端口的 包括该解复用的滤波器的上行光通道上， 至少有一个透射波段包含基础波段 从将所述两个上行波段光信号解复用的滤波器到升级光线路终端端口的 包括该解复用的滤波器的上行光通道上， 至少有一个透射波段包含升级波段 的上行波段且反射波段包含基础波段的上行波段的滤波器；
从遗留光线路终端端口到将所述两个下行波段光信号复用的滤波器的包 括该复用的滤波器的下行光通道上， 至少有一个透射波段包含基础波段的下 行波段且反射波段包含升级波段的下行波段的滤波器； 以及
从升级光线路终端端口到将所述两个下行波段光信号复用的滤波器的包 括该复用的滤波器的下行光通道上， 至少有一个透射波段包含升级波段的下 行波段且反射波段包含基础波段的下行波段的滤波器。
进一步地， 上述波分复用器还可具有以下特点， 所述波分复用器包括第 一滤波器、 第二滤波器、 第三滤波器和第四滤波器， 且在升级光线路终端端 口与第一滤波器的公共端之间， 第一滤波器的反射端与第四滤波器的透射端 或公共端之间， 第四滤波器的公共端或透射端与第三滤波器的反射端之间， 第一滤波器的透射端与第二滤波器的反射端之间， 遗留光线路终端端口与第 二滤波器的透射端之间， 第二滤波器的公共端与第三滤波器的透射端之间， 以及所述波分复用器的公共端口与第三滤波器的公共端之间存在光通道。
进一步地， 上述波分复用器还可具有以下特点， 所述第一滤波器为带通 或边带滤波器， 透射波段包括升级波段的下行波段， 反射波段包括升级波段 的上行波段和基础波段； 所述第二滤波器为边带滤波器， 透射波段包括升级 波段的上行波段和基础波段， 反射波段包括升级波段的下行波段； 所述第三 滤波器为边带滤波器， 透射波段包括升级波段的下行波段和基础波段， 反射 波段包括升级波段的上行波段； 所述第四滤波器为带通或边带滤波器， 透射 波段包括升级波段的上行波段， 反射波段包括升级波段的下行波段和基础波 段； 或者
所述第一滤波器为带通或边带滤波器， 透射波段包括升级波段的上行波 段， 反射波段包括升级波段的下行波段和基础波段； 第二滤波器为边带滤波 器， 透射波段包括升级波段的下行波段和基础波段， 反射波段包括升级波段 的上行波段； 第三滤波器为边带滤波器， 透射滤波包括升级波段的上行波段 和基础波段， 反射波段包括升级波段的下行波段； 第四滤波器为带通或边带 滤波器， 透射波段包括升级波段的下行波段， 反射波段包括基础波段和升级 滤波和上行波段。
进一步地， 上述波分复用器还可具有以下特点， 所述波分复用器包括第 一滤波器、 第二滤波器、 第三滤波器和第四滤波器， 且在升级光线路终端端 口与第一滤波器的公共端之间， 第一滤波器的反射端与第三滤波器的透射端 之间， 第一滤波器的透射端与第二滤波器的反射端之间， 第二滤波器的透射 端与第四滤波器的透射端或公共端之间， 第二滤波器的公共端与第三滤波器 的反射端之间， 第三滤波器的公共端与所述波分复用器的公共端口之间， 以 及第四滤波器的公共端或透射端与遗留光线路终端端口之间存在光通道。
进一步地， 上述波分复用器还可具有以下特点， 所述第一滤波器为带通 或边带滤波器， 透射波段包括升级波段的下行波段， 反射波段包括升级波段 的上行波段和基础波段； 所述第二滤波器为边带滤波器， 透射波段包括升级 波段的上行波段和基础波段， 反射波段包括升级波段的下行波段； 所述第三 滤波器为带通或边带滤波器， 透射波段包括升级波段的上行波段， 反射波段 包括升级波段的下行波段和基础波段； 所述第四滤波器为边带滤波器， 透射 波段包括升级波段的下行波段和基础波段， 反射波段包括升级波段的上行波 段； 或者
所述第一滤波器为带通或边带滤波器， 透射波段包括升级波段的上行波 段， 反射波段包括升级波段的下行波段和基础波段； 所述第二滤波器为边带 滤波器， 透射波段包括升级波段的下行波段和基础波段， 反射波段包括升级 波段的上行波段； 所述第三滤波器为带通或边带滤波器， 透射波段包括升级 波段的下行波段， 反射波段包括升级波段的上行波段和基础波段； 所述第四 滤波器为边带滤波器， 透射波段包括升级波段的上行波段和基础波段， 反射 波段包括升级波段的下行波段。
进一步地， 上述波分复用器还可具有以下特点， 所述波分复用器包括第 一滤波器、 第二滤波器、 第三滤波器和第四滤波器， 且在升级光线路终端端 口与第一滤波器的公共端之间， 第一滤波器的反射端与第二滤波器的透射端 或公共端之间， 第一滤波器的透射端与第四滤波器的反射端之间， 第二滤波 器的公共端或透射端与第三滤波器的反射端之间， 第三滤波器的公共端与第 四滤波器的透射端之间， 第三滤波器的透射端与遗留光线路终端端口之间， 以及第四滤波器的公共端与所述波分复用器的公共端口之间存在光通道。
进一步地， 上述波分复用器还可具有以下特点， 所述第一滤波器为带通 或边带滤波器， 透射波段包括升级波段的上行波段， 反射波段包括升级波段 的下行波段和基础波段； 所述第二滤波器为带通或边带滤波器， 透射波段包 括升级波段的下行波段， 反射波段包括升级波段的上行波段和基础波段； 所 述第三滤波器为带通或边带滤波器， 透射波段包括升级波段的上行波段和基 础波段，反射波段包括升级波段的下行波段； 所述第四滤波器为边带滤波器， 透射波段包括升级波段的下行波段和基础波段， 反射波段包括升级波段的上 行波段； 或者
所述第一滤波器为带通或边带滤波器， 透射波段包括升级波段的下行波 段， 反射波段包括升级波段的上行波段和基础波段； 所述第二滤波器为带通 或边带滤波器， 透射波段包括升级波段的上行波段， 反射波段包括升级波段 的下行波段和基础波段； 所述第三滤波器为边带滤波器， 透射波段包括升级 波段的下行波段和基础波段， 反射波段包括升级波段的上行波段； 所述第四 滤波器为边带滤波器， 透射波段包括升级波段的上行波段和基础波段， 反射 波段包括升级波段的下行波段。
进一步地， 上述波分复用器还可具有以下特点， 所述波分复用器包括一 带通滤波器， 该带通滤波器的透射端与遗留光线路终端端口之间， 公共端与 所述波分复用器的公共端口之间， 以及反射端与升级光线路终端端口之间具 有光通道； 且该带通滤波器的透射波段包括基础波段， 反射波段包括升级波 段； 或者
该带通滤波器的透射端与升级光线路终端端口之间， 公共端与所述波分 复用器的公共端口之间，以及反射端与遗留光线路终端端口之间具有光通道， 且该带通滤波器的透射波段包括升级波段， 反射波段包括基础波段。
进一步地， 上述波分复用器还可具有以下特点， 所述波分复用器中的滤 波器构成及其光谱特性为以下几种方式中的一种： 第一种， 所述波分复用器包括第一滤波器、 第二滤波器和第三滤波器， 第一滤波器的透射波段包括升级波段的下行波段， 反射波段包括升级波段的 上行波段和基础波段； 第二滤波器的透射波段包括升级波段的上行波段， 反 射波段包括升级波段的下行波段和基础波段； 第三滤波器的透射波段包括基 础波段， 反射波段包括升级波段； 连接上， 在升级光线路终端端口与第一滤 波器的公共端之间， 第一滤波器的反射端与第二滤波器的透射端之间， 第一 滤波器的透射端与第二滤波器的反射端之间， 第二滤波器的公共端与第三滤 波器的反射端之间， 第三滤波器的透射端与遗留光线路终端端口之间， 以及 第三滤波器的公共端与所述波分复用器的公共端口之间存在光通道；
第二种， 将第一种方式中的第一滤波器和第二滤波器位置互换， 各滤波 器的光语特性与第一种方式相同；
第三种， 所述波分复用器包括第一滤波器和第二滤波器， 第一滤波器的 透射波段包括基础波段， 反射波段包括升级波段； 第二滤波器的透射波段包 括升级波段， 反射波段包括基础波段； 连接上， 遗留光线路终端端口与第一 滤波器的透射端之间， 所述波分复用器的公共端口与第一滤波器的公共端之 间， 升级光线路终端端口与第二滤波器的透射端或公共端之间， 以及第二滤 波器的公共端或透射端与第一滤波器的反射端之间存在光通道；
第四种， 所述波分复用器包括第一滤波器和第二滤波器， 第一滤波的透 射波段包括升级波段， 反射波段包括基础波段片； 第二滤波器的透射波段包 括基础波段， 反射波段包括升级波段； 连接上， 第一滤波器的透射端与升级 光线路终端端口之间， 第一滤波器的反射端与第二滤波器的透射端或公共端 之间， 第一滤波器的公共端与所述波分复用器的公共端之间， 以及第二滤波 器的公共端或透射端与遗留光线路终端端口之间存在光通道；
第五种， 所述波分复用器包括第一滤波器、 第二滤波器和第三滤波器， 第一滤波器的透射波段包括升级波段， 反射波段包括基础波段； 第二滤波器 的透射波段包括升级波段的上行波段和基础波段， 反射波段包括升级波段的 下行波段； 第三滤波器的透射波段包括升级波段的下行波段和基础波段， 反 射波段包括升级波段的上行波段； 连接上， 在第一滤波器的透射端与升级光 线路终端端口之间， 第一滤波器的公共端与所述波分复用器的公共端之间， 所述第一滤波器的反射端与所述第二滤波器的公共端或透射端之间， 第二滤 波器的透射端或公共端与第一滤波器的公共端或透射端之间， 以及第一滤波 器的透射端或公共端与遗留光线路终端端口之间存在光通道；
第六种， 将第五种方式中的第二滤波器和第三滤波器位置互换， 各滤波 器的光语特性与第五种方式相同。
进一步地， 上述波分复用器还可具有以下特点， 其特征在于， 所述波分 复用器中的滤波器均为薄膜滤波片。
进一步地， 上述波分复用器还可具有以下特点， 其特征在于：
所述升级波段的上行波段为 1260 nm至 1280 nm波段， 所述升级波段的 下行波段为 1550nm至 1580nm波段； 所述基础波段的上行波段为 1290 nm至 1330 匪波段也即 O波段， 所述基础波段的下行波段为 1480 nm至 1500 nm 波段也即 S波段。
本发明提供的 WDM1 实现了基础波段与升级波段的光信号的波分复用 和解复用功能。 使现有的时分复用无源光网络的光分配网络能够同时传送下 一代无源光网络， 实现 TDM-PON向 NG-PON平滑演化， 同时能够对已部署 的 TDM-PON系统提供后续网络兼容。 在一些实施例中， 通过合理地使用薄 膜滤波片和选择滤波片的光谱特性， 可以较低的成本来满足光信号工作波段 的高隔离度要求， 而通过适当设置滤波片的个数及其光语特性， 还可以兼顾 隔离度和对光网络插入损耗的要求。 本发明实施例中釆用简单实用可行的技 术实现了 WDM1 , 且成本低、 可靠性高， 便于使用和系统升级。
附图概述
图 1为本发明实施例 WDM1的外部接口的结构示意图；
图 2 ( a )是本发明第一实施例的 WDM1 的结构示意图， 示出了其上行 和下行方向的光传输路径； 图 2 ( b )〜图 2 ( 1 )为第一实施例及其变换方式 中各个滤波片的光谱示意图；
图 3 ( a )是本发明第二实施例的 WDM1的结构示意图； 图 3 ( b )〜图 3 (d)为第二实施例中各个滤波片的光谱示意图；
图 4 (a)是本发明第三实施例的 WDM1的结构示意图； 图 4 (b)为第 三实施例中滤波片的光谱示意图；
图 5 (a)是本发明第四实施例的 WDM1的结构示意图； 图 5 (b)为第 四实施例中滤波片的光语示意图；
图 6 (a)是本发明第五实施例的 WDM1的结构示意图； 图 6 (b)〜图 6 (c)为第五实施例中各个滤波片的光谱示意图；
图 7 (a)是本发明第六实施例的 WDM1的结构示意图； 图 7 (b)〜图 7
(c)为第六实施例中各个滤波片的光谱示意图；
图 8 (a)是本发明第七实施例的 WDM1的结构示意图； 图 8 (b)〜图 8
(d)为第七实施例中各个滤波片的光语示意图；
图 9 (a)是本发明第八实施例的 WDM1的结构示意图； 图 9 (b)〜图 9 (d)为第八实施例中各个滤波片的光语示意图；
图 10 (a)是本发明第九实施例的 WDM1 的结构示意图； 图 10 (b) ~ 图 10 (d)为第九实施例中各个滤波片的光语示意图；
图 11 (a)是本发明第十实施例的 WDM1 的结构示意图； 图 11 (b)〜 图 11 (i)为第十实施例及其变换方式中各个滤波片的光语示意图；
图 12 (a)是本发明第十一实施例的 WDM1的结构示意图； 图 12 (b) ~ 图 12 (e)为第十一实施例中各个滤波片的光谱示意图；
图 13是本发明实施例 WDM1实现 NG-PON兼容 G-PON的网络结构图。
本发明的较佳实施方式
下面结合附图对本发明的具体实施方式进行详细说明。
当单纤的现有 TDM-PON向 NG-PON演化时，将引入三个波段，分别为： NG-PON的上行波段 ( 1260匪至 1280匪 ) , CATV信号的下行波段 ( 1550 匪至 1560匪） 以及 NG-PON的下行 波段（ 1575匪 至 1580匪） 。 因此 文中的升级波段包括上行波段和下行波段，其中上行波段为 1260 nm至 1280 匪波段， 下行波段为 1550匪至 1580匪波段， 包括了 1550 ■至 1560 nm 波段和 1575 nm至 1580 nm波段。 而基础波段也包括上行波段和下行波段， 上行波段为 1290匪至 1330匪波段也即 O波段，下行波段为 1480 nm至 1500 匪波段也即 S波段。 需要说明的是， 上述波长规划也可以有变化， 只要以上 4个波段的分布关系不变， 本发明的 WDM1也是可以适用的。
为了实现单纤的 TDM-PON向 NG-PON的平滑演化， 其关键问题之一是 需要在光线路终端和分光器之间插入一个 WDM1 , 实现基础波段与升级波段 的光信号的波分复用功能， 并尽量满足低成本、 高可靠性和便于使用和系统 升级的要求。 该波分复用器作为不同波长的光信号的接入点， 需要满足以下 要求：
A. 使 NG-PON的波分复用的光信号与现有 TDM-PON的光信号在现有 的光分配网上实现波分复用和解复用的功能；
B. 基础波段的光信号和升级波段的光信号之间需要高隔离度； 以及
C. 具有低插入损耗。
在目前用作波分复用器的滤波器的制备工艺技术中， 薄膜滤波器（也称 为薄膜滤波片 )比较适用于宽带滤波且制作工艺较成熟， 可以在 WDM1中釆 用。 薄膜滤波片有透射和反射的作用， 相应的工作波段可以称为透射波段和 反射波段。 对于普通的薄膜滤波片来说， 一般透射端的隔离度都很好， 不容 易被其他波段的光信号串扰， 其隔离度可以达到 35dB。 而反射端的隔离度相 对差一些， 为 15dB , 透射波段的光信号可以串扰到反射端， 需要釆取加强的 措施。 而插入损耗与薄膜滤波片的个数成正比。 因此， 在保证隔离度的情况 下， 优先使用最少的滤波片。 下文中的实施例均釆用薄膜滤波片实现， 本发 明并不限制所釆用滤波器的类型， 只要能够达到相同的光谱特性， 也可以应 用于本发明的 WDM1。
在 NG-PON 同时兼容现有 TDM-PON 的网络系统架构中， 中心机房 (Central Office)放置遗留光线路终端与升级光线路终端， 所述 WDM1的外部 接口如图 1所示， 包括遗留光线路终端端口， 升级光线路终端端口和公共端 口：
在下行方向， 基础波段的光信号输入到遗留光线路终端端口， 升级波段 的光信号输入到升级光线路终端端口， 该波分复用器将输入的基础波段的光 信号与升级波段的光信号复用后从公共端口输出， 使两个波段的光信号在单 根光纤中传输， 然后通过分光器等光器件最终传送到各个 ONU设备； 在上行 方向， 波分复用的两个波段的光信号利用同一光纤从 WDM1 的公共端口输 入， WDM1实现解复用后将其中的基础波段和升级波段的光信号分别送至遗 留光线路终端端口与升级光线路终端端口。
基础波段总带宽为 210 nm (下行 S波段的范围在 1480 nm至 1500 nm, 上行 O波段的范围在 1290 nm至 1330 nm ) , 升级波段的上行波段和下行波 段分布在基础波段的两侧（上行波段在 1260 nm至 1280 nm,下行波段在 1550 nm至 1580 nm,此处的下行波段包括两部分， 即 CATV下行波段和 NG-PON 下行波段） 。 由此可得基础波段的上行波段和升级波段的上行波段之间的间 隔较窄大约为 10 nm。 因此基础波段的带宽比较大， 而两个波段之间的波段 间隔比较小。
以下对本发明举例阐述。 应当理解， 以下所描述的优选实例仅用于说明 和解释本发明， 并不用于限定本发明。 如果不冲突， 本申请中的实例及实例 中的特征可以相互组合。
以下结合附图对实现 WDM1的多个实施例的具体结构进行详细说明： 第一实施例
由于 WDM1的制备工艺和电信网络应用的需求以及成本等因素，结合上 述基础波段和升级波段的特点， WDM1可以釆用边带型滤波片和 /或带通型滤 波片组装而成。
图 2 ( a )所示为本第一实施例的 WDM1的结构及其上 /下行方向的工作 原理， 该 WDM1包括四个薄膜滤波片， 即带通滤波片 fl l , 边带滤波片 fl2 , 边带滤波片 fl3和带通滤波片 fl4。 边带型或带通型的滤波片均可以是三端器 件， 包括透射端、 反射端和公共端。 某些带通或边带滤波片如 fl4也可以是 两端器件， 包括透射端和公共端。 图中， 反射端和公共端在滤波片的同一侧， 透射端在另一侧。 与透射端的线上箭头朝向相反的 （指朝向或背离滤波片） 为反射端。
请参见图 2 ( b )〜图 2 ( e ) 的光语示意图。 带通滤波片 fl l的透射波段 包括 1550匪至 1580匪，反射波段包括 1260匪至 1500匪；边带滤波片 fl2 的透射波段包括 1260匪至 1500匪， 1550匪至 1580匪位于其反射波段上； 1290匪至 1580匪位于边带滤波片 fl3的透射波段， 1260 nm至 1280 nm位 于 fl3的反射波段； 1260 nm至 1280 nm位于带通滤波片 fl4的透射波段， 1290 匪至 1580匪位于 fl4的反射波段。
参照图 2 ( a ) , 升级光线路终端端口与带通滤波片 fl l的公共端之间， 带通滤波片 fl l的反射端与带通滤波片 fl4的透射端之间， 带通滤波片 fl4的 公共端与边带滤波片 fi3的反射端之间，带通滤波片 fl l的透射端与边带滤波 片 fl2的反射端之间， 遗留光线路终端端口与边带滤波片 fl2的透射端之间， 边带滤波片 fl2的公共端与边带滤波片 fl3的透射端之间， WDM1公共端口 与边带滤波片 fl3的公共端之间存在光通道。 fl4的公共端和透射端可以互换。 图中为了方便表示， 有的光通道釆用折线来表示， 在实际的器件中光通道尽 量釆用直线， 但也不排除通过增设反射器件， 使得一条光通道的光信号的传 输方向发生变化的情况。 其他各实施例同此。 图中的箭头是以下行方向为例， 上行方向将所有箭头方向反向即可。
在下行方向上， NG-PON的下行信号 （波长在 1550 匪至 1580 nm )从 WDM1的升级光线路终端端口入射后， 进入带通滤波片 fl l的公共端， 经过 带通滤波片 fl l 的透射后进入边带滤波片 fl2并经其反射后进入边带滤波片 A3的透射端， 经过透射后由边带滤波片 fl3的公共端输出到 WDM1的公共 端口； 同时， G-PON的下行波长（波段在 1480匪至 1500匪） 从 WDM1的 遗留光线路终端端口入射后进入边带滤波片 fl2的透射端， 由边带滤波片 fl2 的公共端输出后进入边带滤波片 fl3 的透射端， 经透射后从边带滤波片 fl3 的公共端输出到 WDM1的公共端口。 因此从 WDM1的公共端口输出的信号 为 NG-PON的下行信号和 G-PON的下行信号的波分复用信号。
在上行方向上， 从 WDM1 公共端口输入的波分复用信号包括 NG-PON 的上行信号 (上行波段在 1260 nm至 1280 nm )和 G-PON的上行信号 (波段 在 1290 nm至 1330 nm ) , 其中 NG-PON的上行信号从 WDMl的公共端口入 射后进入边带滤波片 fl3的公共端，经过边带滤波片 fl3反射后进入带通滤波 片 fl4的公共端，经 fl4透射后由 fl4透射端输出到带通滤波片 fl l的反射端， 经过 fl 1反射后由 fl 1的公共端输出到 WDM1的升级光线路终端端口；同时， G-PON的上行信号从 WDM1的公共端口入射后进入边带滤波片 fl3的公共 端， 由其透射端输出并进入边带滤波片 fl2的公共端， 由边带滤波片 fl2透射 后从其透射端输出到 WDM1的遗留光线路终端端口。 完成了解复用。
本实施例的 WDM1器件在实现波分复用和解复用的同时，也能够满足升 级波段和基础波段之间的高隔离度的要求。 需要考虑的是升级波段的上行波 段和基础波段的上行波段之间， 以及基础波段的下行波段和升级波段的下行 波段之间的串扰。
上文中已提到滤波片透射端的隔离度高， 如果从将两个上行波段光信号 解复用的滤波片到 WDM1的遗留光线路终端端口的上行光通道上（包括该解 复用的滤波片） ， 至少有一个透射波段包含基础波段的上行波段且反射波段 包含升级波段的上行波段的滤波片， 从将两个上行波段光信号解复用的滤波 片到 WDM1的升级光线路终端端口（包括该解复用的滤波片）的上行光通道 段的上行波段的滤波片， 则使用普通的滤波片即可达到两个上行波段之间的 隔离度要求。如果从 WDM1的遗留光线路终端端口到将两个下行波段光信号 复用的滤波片 （包括该复用的滤波片） 的下行光通道上至少有一个透射波段
WDM1的升级光线路终端端口到将两个下行波段光信号复用的滤波片 （包括 该复用的滤波片） 的下行光通道上至少有一个透射波段包含升级波段的下行 波段且反射波段包含基础波段的下行波段的滤波片， 则可以达到两个下行波 段之间的隔离度要求。 下文中将该上述 4个条件统称为第一隔离度条件。
本实施例是可以满足这个要求的， 将两个上行波段光信号解复用的滤波 片是 fl3 ,从 fl3到遗留光线路终端端口的上行光通道经过的滤波片包括 fl3 , 和 fl2,基础波段的上行波段位于 fl3的透射波段且升级波段的上行波段位于 A3的反射波段。从 f!3到升级光线路终端端口的上行光通道经过的滤波片包 括 fl3,fl4和 fl l , 其中升级波段的上行波段位于 fl4的透射波段且基础波段 的上行波段位于 fl4 的反射波段。 此外， 将两个下行波段光信号复用的滤波 片是 fl2 (将两个信号复用指输入该滤波片时两个信号是分离的， 输出时该两 个信号已合一） ， 从遗留光线路终端端口到 fl2 的下行光通道经过的滤波片 为 fl2, fl2的透射波段包括基础波段的下行波段且反射波段包括升级波段的 下行波段， 从升级光线路终端端口到 fl2的下行光通道经过的滤波片包括 fl l 和 fl2, fl l的透射波段包括升级波段的下行波段且反射波段包括基础波段的 下行波段。 因此， 本实施例可以保证两个上行波段之间以及两个下行波段之 间的隔离度， 所有的滤波片均可釆用普通的滤波片实现，从而降低 WDM1的 成本。 对上述滤波片的类型和光谱特性进行一些变化， 可以得到一些变换方 式：
变换方式一， 结构图仍如图 2 ( a )所示， 光谱图如图 2 ( f )〜图 2 ( 1 ) 所示， 将带通滤波片 fl l改为边带滤波片， 1550nm至 1580nm位于其透射波 段， 1260nm至 1500nm位于其反射波段， 带通滤波片 fl4改为边带滤波片， 1260nm至 1280nm位于其透射波段， 1290nm至 1580nm位于其反射波段。 边 带滤波片 fl2和 fl3的类型和光谱特性都不变。因为该变换方式的滤波片光谱 特性中，基础波段的上、下行波段和升级波段的上、下行波段（也称为 WDM1 的相关 4个波段） 的透射或反射关系不变， 因此其性能基本是相同的。 以上 fl 1和 fl4也可以只改其中的一个。
变换方式二， 结构图仍如图 2 ( a )所示， fl l~fl4均为边带滤波片， 光谱 特性如下： 边带滤波片 fl l的透射波段包括 1260 nm至 1280 nm, 反射波段包 括 1290 nm至 1580 nm;边带滤波片 fl2的透射波段包括 1290 nm至 1580 nm, 反射波段包括 1260 匪至 1280匪； 边带滤波片 fl3的透射波段包括 1260 匪 至 1500 nm, 反射波段包括 1550匪至 1580 nm; 边带滤波片 fl4的透射波段 包括 1550匪至 1580匪， 反射波段包括 1260匪至 1500匪。
变换方式三， 在变换方式二的基础上， 将边带滤波片 fl l和 /或边带滤波 片 fl4改为带通滤波片， 且在带通滤波器 fl l和 fl4的光语特性中相关 4个波 段的透射或反射关系与变换方式二中的 fl l和 fl4相同。
同上分析， 也可以实现 WDM1的功能并达到高隔离度的要求。 同样， 所述的 WDM1器件模块可达到的参数如表 1所示。
表 1 : 图 2 ( a )所示的 WDM1器件模块参数
Figure imgf000016_0001
第二实施例
本实施例的 WDM1包括三个薄膜滤波片， 分别为边带滤波片 £21、 边带 滤波片 £22以及带通滤波片 £23。 图 3 ( b )〜图 3 ( d )分别示出了各个滤波片 的光谱。其中， 1550 nm至 1580 nm位于边带滤波片 £21的透射波段， 1260 nm 至 1500 nm位于其反射波段； 1260 nm至 1280 nm位于边带滤波片 £22的透射 波段， 1290匪至 1580匪位于其反射波段； 1290匪至 1500 nm位于带通滤 波片 £23的透射波段， 1260匪至 1280匪波段和 1550匪至 1580 nm波段位 于 3的反射波段。
WDM1的升级光线路终端端口与边带滤波片 £21的公共端之间， 边带滤 波片 £21的反射端与边带滤波片 £22的透射端之间， 边带滤波片 £21的透射端 与边带滤波片 £22的反射端之间， 边带滤波片 £22的公共端与带通滤波片 £23 的反射端之间， 带通滤波片 £23的透射端与 WDM1的遗留光线路终端端口之 间， 以及带通滤波片 £23的公共端与 WDM1的公共端口之间存在光通道。
在下行方向上， NG-PON的下行信号 （波段在 1550-1580匪）从 WDM1 的升级光线路终端端口入射后， 进入边带滤波片 £21 的公共端， 经过边带滤 波片 £21透射后进入边带滤波片 £22的反射端， 经过边带滤波片 £22反射后从 其公共端输出到带通滤波片 £23的反射端， 经 £23反射后由带通滤波片 £23的 公共端输出到 WDM1的公共端口；同时， G-PON的下行信号（波段在 1480 nm 至 1500 nm )从该 WDM 1的遗留光线路终端端口入射后进入带通滤波片 £23 的透射端， 经过带通滤波片 £23的透射后由其公共端输出到 WDM1的公共端 口输出， 因此从 WDM1 的公共端口输出的信号为 NG-PON 的下行信号和 G-PON的下行信号的波分复用信号。
在上行方向上， 从 WDM1 公共端口输入的波分复用信号包括 NG-PON 的上行信号和 G-PON的上行信号， 其中 NG-PON的上行信号从 WDM1的公 共端口入射后进入带通滤波片 £23的公共端，经过带通滤波片 £23反射由其反 射端输出后进入边带滤波片 £22的公共端，经透射后由边带滤波片 £22的透射 端输出到边带滤波片 £21的反射端，并经边带滤波片 £21反射后由其公共端输 出到 WDM1的升级光线路终端端口； 同时， G-PON的上行信号从 WDM1的 公共端口入射后进入带通滤波片 £23的公共端，经过带通滤波片 £23透射后由 带通滤波片 £23透射端输出到 WDM1的遗留光线路终端端口。
可以看出， 该实施例也是满足上述第一隔离度条件的。 由于薄膜滤波器 的制作工艺难度与滤波器的带通宽度、 隔离度等要求成正比， 而跟保护带宽 间隔等成反比。 边带滤波片 £21和边带滤波片 £22增强了反射方向的隔离度， 间接降低了带通滤波片 £23反射方向的隔离度的要求， 从而降低了薄膜滤波 器的工艺制备难度， 这能够使薄膜滤波器的镀膜层数较低， 加工难度降低， 第一实施例中各滤波片也是如此。 且本实施例中的带通滤波片 £23 由于带通 宽度较大， 实现较第一实施例的滤波片要困难， 第一实施例的 WDM1价格相 对便宜。
本实施例所述的 WDM1器件模块所达到的参数如表 2所示。
表 2: 图 2 ( b )所示的 WDM1器件模块参数
Figure imgf000018_0001
第三实施例 釆用更先进的镀膜工艺时， 可以直接釆用带通滤波片 βΐ 实现上述的波 分复用 /解复用功能， 即利用带通薄膜滤波片制成宽带通高隔离度的 WDM1 , 实现基础波段和升级波段的波分复用 /解复用功能及高隔离度的要求， 此 WDM1的上下行工作原理示意图如图 4 ( a )所示， 该 βΐ的透射端与 WDM1 遗留光线路终端端口之间， β 1的公共端与 WDM1的公共端口之间， β 1的反 射端与 WDM1的升级光线路终端端口之间具有光通道。
图 4 ( b )为 βΐ的光语示意图， 其中 1290匪至 1500匪波段位于 βΐ的 透射波段， 1260匪至 1280匪波段和 1550匪至 1580匪波段位于 βΐ的反射 波段。通过该带通滤波片 βΐ , 可以直接实现基础波段和升级波段光信号的复 用和解复用。
本实例釆用了一片带通滤波片 βΐ实现上述的波分复用 /解复用功能， 也 可以釆用多片 βΐ组装在一起实现上述的波分复用 /解复用功能。
第四实施例
该实施例的 WDM1中也是只釆用了一个带通滤波片 f41 , 如图 5 ( a )所 示， 该 f41的透射端与 WDM1的升级光线路终端端口之间， f41的公共端与 WDM1的公共端口之间， f41的反射端与 WDM1的遗留光线路终端端口之间 具有光通道。
图 5 ( b )为 f41的光语示意图， 其中 1290匪至 1500匪波段位于 f41的 反射波段， 1260匪至 1280匪波段和 1550匪至 1580匪波段位于 f41的透射 波段。通过该带通滤波片 f41 , 可以直接实现基础波段和升级波段光信号的复 用和解复用。
第五实施例
如图 6 ( a )所示， 本实施例的 WDM1中包括带通滤波片 f51和带通滤波 片 f52。 1290匪至 1500匪波段位于 f51的透射波段， 1260匪至 1280匪波段 和 1550匪至 1580匪波段位于 f51的反射波段。 1290匪至 1500匪波段位于 f52的反射波段， 1260匪至 1280匪波段和 1550匪至 1580匪波段位于 f52 的透射波段。 在连接上， WDM1的遗留光线路终端端口与 f51的透射端之间， WDM1 的公共端口与 f51的公共端之间， WDM1的升级光线路终端端口与 f52的透 射端之间， f52的公共端与 f51的反射端之间存在光通道。 f52的公共端和透 射端可以互换。
基于图 6 ( a ) 中指示的光信号传输路径（这里不再详细描述， 从图中可 以清楚的看出） ， 可以实现升级波段和基础波段光信号的复用和解复用， 并 且也满足上述第一隔离度条件， 插入损耗较小。
第六实施例
如图 7 ( a )所示， 这个实施例的 WDM1包括带通滤波片 f61和 f62, 其 中 f61的光谱特性与第五实施例中的 f52相同， f62与的光语特性与第五实施 例中的 f51相同。
相应的，各滤波片之间及滤波片与 WDM1的端口之间的连接关系有所变 化，其中带通滤波片 f61的透射端与 WDM1的升级光线路终端端口之间， f61 的反射端与 f62的透射端之间， f61的公共端与 WDM1的公共端之间， f62的 公共端与 WDM1的遗留光线路终端端口之间存在光通道。 f62的公共端和透 射端可以互换。
同样地，本实施例的 WDM1也可以实现升级波段和基础波段光信号的复 用和解复用， 并且也满足上述第一隔离度条件， 插入损耗较小。
第七实施例
本实施例 WDM1的结构如图 8 ( a )所示， 包括边带滤波器 Π1、 边带滤 波器 Π2和带通滤波器 Π3。 各滤波片的光谱特性如图 8 ( b ) ~ ( d )所示。 可 以看出， 该实施例与第二实施例的结构基本是相同的， 相当于把第二实施例 中的边带滤波器 f51与 f52互换了一下位置，性能不受影响。在此不再进行详 细的说明。
第八实施例 如图 9 ( a )所示， 本实施例 WDM1包括带通滤波片 f81、 边带滤波片 f82 和边带滤波片 f83。f82的透射波段包括 1260nm至 1500nm,反射段包括 1550nm 至 1580匪； f83的透射波段包括 1290匪至 1580匪， 反射段包括 1260匪至 1280匪。
本实施例的 f81和第六实施例的 f61的光语特性是相同的，而两个串接的 边带滤波片 f82和 f83的作用基本与 f62相同， 叠加后的光语特性也与 f62相 同。 只是边带滤波片 f82和 f83更容易实现。 因此， 本实施例的 WDM1也可 以实现升级波段和基础波段光信号的复用和解复用， 并且也满足上述第一隔 离度条件。
第九实施例
本实施例只是将第八实施例中的边带滤波片 f82和边带滤波片 f83的位置 互换， 在此不再详细说明。
第十实施例
如图 11(a)所示， 本实施例 WDM1 中包括边带滤波片 fl01、 fl02、 fl03 和 f!04。 如图 11 ( b ) ~ ( e )所示， 边带滤波片 flOl的透射波段包含 1550nm 至 1580匪， 反射波段包含 1260匪至 1500匪； 边带滤波片 fl02的透射波段 包含 1260匪至 1500匪， 反射波段包含 1550匪至 1580匪； 边带滤波片 fl03 的透射波段包含 1260匪至 1280匪， 反射波段包含 1290匪至 1580匪； 边带 滤波片 fl04的透射波段包含 1290匪至 1580匪， 反射波段包含 1260nm至 1280匪。
WDM1 的升级光线路终端端口与 flOl 的公共端之间， flOl 的反射端与 fl03的透射端之间， flOl的透射端与 fl02的反射端之间， fl 02的透射端与 fl04 的透射端之间， fl02的公共端与 fl03的反射端之间， fl03的公共端与 WDM1 的公共端口之间， fl 04的公共端与 WDM1的遗留光线路终端端口之间存在光 通道， fl04的公共端和透射端可以互换。
根据图 11 ( a ) ~ ( e ) 可以看出， 本实施例的 WDM1可以实现升级波段 和基础波段的光信号的波分复用和解复用， 并且也满足上述的第一隔离度条 件。 本实施例所用滤波片均为边带滤波器， 成本较低。
通过对滤波片的类型和 /或光谱特性的变化， 该实施例还有一些变换方 式， 例如：
变换方式一， 结构图仍如图 11 ( a )所示， 各个滤波片 fl01~fl04的连接 关系不变， 将边带滤波片 flOl改为透射波段包含 1550nm至 1580nm, 反射波 段包含 1260nm至 1500nm的带通滤波片， 将边带滤波片 fl03改为透射波段 包含 1260nm至 1280nm,反射波段包含 1290nm至 1580nm的带通滤波片， 边 带滤波片 fl02和 fl04不变。 明显， 该变换后的 WDM1与变换前的 WDM1 的性能^^本相同的。 也可以只变 flOl和 fl03中的一个。
变换方式二， 结构图仍如图 11 ( a )所示， 各个滤波片 fl01~fl04的连接 关系不变， 将各个边带滤波片的光语特征改为如图 11 ( f ) 〜 ( 1 )所示， 即： 边带滤波片 flOl的透射波段包含 1260匪至 1280匪， 反射波段包含 1290nm 至 1580nm; 边带滤波片 fl02的透射波段包含 1290nm至 1580nm, 反射波段 包含 1260匪至 1280匪；边带滤波片 fl03的透射波段包含 1550匪至 1580nm, 反射波段包含 1260nm至 1500nm; 边带滤波片 fl04的透射波段包含 1260nm 至 1500匪， 反射波段包含 1550匪至 1580匪。 这种变换方式下， WDM1也 可以实现升级波段和基础波段的光信号的复用和解复用， 并且仍满足上述第 一隔离度条件。
变换方式三， 在变换方式二的基础上， 将边带滤波片 flOl改为透射波段 包含 1260nm至 1280nm,反射波段包含 1290nm至 1580nm的带通滤波片； 和 /或， 将边带滤波片 fl03可以改为透射波段包含 1550nm至 1580nm, 反射波 段包含 1260nm至 1500nm的带通滤波片。
第十一实施例
本实施例的 WDM1的结构如图 12 ( a )所示， 包括带通滤波片 fl l l、 带 通滤波片 fl l2、 边带滤波片 fl l3和边带滤波片 fl l4。 光语特性如图 12 ( b ) -12 ( e )所示， 带通滤波片 fi l l的透射波段包括 1260nm至 1280nm, 反射波 段包括 1290nm至 1580nm; 带通滤波片 fll2 的透射波段包括 1550匪至 1580匪，反射波段包括 1260匪至 1500匪； 边带滤波片 fll3的透射波段包括 1260匪至 1500匪， 反射波段包括 1550匪至 1580匪； 边带滤波片 fll4的透 射波段包括 1290匪至 1580匪， 反射波段包括 1260匪至 1280匪。
连接关系方面， WDM1的升级光线路终端端口和带通滤波片 fl 11的公共 端之间， fill的透射端与 fll4的反射端之间， fill的反射端与 fll2的透射端 (或公共端 )之间， fll2的公共端 （或透射端）与 fll3的反射端之间， fll3 的透射端与遗留光线路终端端口之间， fll3的公共端与 fll4的透射端之间， fll4的公共端与 WDM1的公共端口之间具有光通道。
通过对滤波片的类型和 /或光谱特性的变化， 该实施例还有一些变换方 式， 例如：
变换方式一， flll~fll4的连接关系仍如图 12 (a)所示， 但将带通滤波 片 fill 改为边带滤波片， 透射波段包括 1260匪至 1280匪， 反射波段包括 1290nm至 1580nm; 和 /或， 将带通滤波片 fll2改为边带滤波片， 透射波段包 括 1550匪至 1580匪， 反射波段包括 1260匪至 1500匪。 边带滤波片 fll3 和 fll4的类型和光谱特性都不变。
变换方式二， flll~fll4的连接关系仍如图 12 (a)所示， fill仍为带通 滤波片，但透射波段包括 1550匪至 1580匪，反射波段包括 1260匪至 1500匪； fll2仍为带通滤波片， 但透射波段包括 1260匪至 1280匪， 反射波段包括 1290nm至 1580nm; fl 13仍为边带滤波片 ,但透射波段包括 1290nm至 1580nm, 反射波段包括 1260nm至 1280nm; fll4仍为边带滤波片， 但透射波段包括 1260匪至 1500匪， 反射波段包括 1550匪至 1580匪。
变换方式三， 在变换方式二的基础上， 将带通滤波片 fill和 /或 fl 12改 为边带滤波片，且改后的边带滤波片 fill和 fll2光谱特性中相关 4个波段的 透射或反射关系与变换方式二中的 fill和 fll2相同。 将第十一实施例及其三个变换方式的连接关系与各个滤波片的光语特性 结合分析，即可看出该实施例及其所有变换方式的 WDM1也可以实现升级波 段和基础波段的光信号的复用和解复用， 并且满足上述第一隔离度条件。 以上虽然给出了 4艮多结构的实施例， 但本领域技术人员都可以了解， 这 里可能的组合是很多的，只要能够实现波分复用和解复用并满足隔离度要求， 都可以用于本发明的 WDM1。
下面以 G-PON 网络为例， 描述利用本发明实施例的波分复用器实现
NG-PON兼容 TDM-PON网络结构示意图， 如图 13所示。
所述 NG-PON兼容 G-PON网络结构包括目前基于基础波段的 G-PON系 统网络架构与基于升级波段的下一代 NG-PON 系统网络架构， 其中 G-PON 系统网络架构包括 G-PON OLT、 WDM1、 分光器和 G-PON ONU; 下一代 NG-PON系统网络架构包括 NG-PON OLT、 CATV、 WDM1、分光器和 NG-PON ONU, 其中， 实现 TDM-PON到 NG-PON的平滑升级需引入 WDM1 , 通过 复用 /解复用实现网络的兼容。
对于 G-PON系统， 在下行方向， 中心波长为 1490nm±10nm的下行波长 的光信号从 G-PON OLT侧由 Tx光模块发射经滤光片 Filter 1再由 WDM1的 遗留光线路终端端口输入，然后由 WDM1的公共端口复用输出经过分光器送 至 G-PON ONU , 最后由与之匹配的 G-PON ONU中滤波片 Filter 3滤出终被 Rx接收； 上行方向同理；
对于 NG-PON系统，在下行方向，波长为 1575nm至 1580nm的下行波长 的光信号从 NG-PON OLT侧由 Tx光模块发射经滤波片 Filter 2后， 与波长为 1550nm至 1560nm 的 CATV下行信号通过一个 WDM器件合波，合波后的信 号 （包括 NG-PON的 1575匪至 1580匪的下行信号和 CATV的 1550匪至 1560nm的下行信号）再由 WDM1的升级光线路终端端口输入，然后由 WDM1 的公共端口复用输出， 经分光器送至 NG-PON ONU, 然后由与之匹配的 NG-PON ONU中的滤波片 Filter 4滤出被 Rx接收。 其上行方向同理， 此处不 在赘述。
因此， 对于 G-PON网络的布局以及现有 G-PON网络的平滑升级， 在极 大地节约了现有 ODN网络资源的情况下，必须引入 WDM1通过复用 /解复用 功能实现两者的兼容。 以上所述， 仅为本发明较佳的具体实施方式， 本领域技术人员可以但本 发明的保护范围并不局限于此， 任何熟悉本技术领域的技术人员在本发明揭 露的技术范围内， 可轻易想到的变化或替换， 都应涵盖在本发明的保护范围 之内。 因此， 本发明的保护范围应该以权利要求书的保护范围为准。
工业实用性
本发明提供的波分复用器实现了基础波段与升级波段的光信号的波分复 用和解复用功能。 使现有的时分复用无源光网络的光分配网络能够同时传送 下一代无源光网络， 实现现有 TDM-PON向 NG-PON平滑演化， 同时能够对 已部署的 TDM-PON系统提供后续网络兼容。 在一些实施例中， 通过合理地 使用薄膜滤波片和选择滤波片的光语特性， 可以较低的成本来满足光信号工 作波段的高隔离度要求， 而通过适当设置滤波片的个数及其光语特性， 还可 以兼顾隔离度和对光网络插入损耗的要求。 本发明实施例中釆用简单实用可 行的技术实现了 WDM1 , 且成本低、 可靠性高， 便于使用和系统升级。

Claims

权 利 要 求 书
1、 一种兼容两种无源光网络的波分复用器， 包括升级光线路终端端口、 遗留光线路终端端口、 公共端口以及一个或多个滤波器， 其中，
所述一个或多个滤波器设置为在下行方向， 将从所述遗留光线路终端端 口输入的基础波段的光信号和从所述升级光线路终端端口输入的升级波段的 光信号进行复用， 并将复用的光信号从所述公共端口输出； 在上行方向， 将 从所述公共端口输入的波分复用的光信号解复用为所述基础波段和升级波段 的光信号， 并将所述基础波段的光信号从所述遗留光线路终端端口输出， 将 所述升级波段的光信号从所述升级光线路终端端口输出；
向传输的上行波段；
从而能够实现使用所述升级波段的下一代无源光网络与使用所述基础波 段的现有时分复用无源光网络的兼容。
2、 如权利要求 1所述的波分复用器， 其中， 所述波分复用器包括多个滤 波器， 所述多个滤波器设置为：
所述多个滤波器中的至少一个， 其在从将所述基础波段的上行波段和所 述升级波段的上行波段的光信号解复用的滤波器到所述遗留光线路终端端口 的上行光通道上的透射波段包含所述基础波段的上行波段， 且反射波段包含 所述升级波段的上行波段；
所述多个滤波器中的至少一个， 其在从将所述基础波段的上行波段和所 述升级波段的上行波段的光信号解复用的滤波器到所述升级光线路终端端口 的上行光通道上的透射波段包含所述升级波段的上行波段， 且反射波段包含 所述基础波段的上行波段；
所述多个滤波器中的至少一个， 其在从所述遗留光线路终端端口到将所 述基础波段的下行波段和所述升级波段的下行波段的光信号复用的滤波器的 下行光通道上的透射波段包含所述基础波段的下行波段， 且反射波段包含所 述升级波段的下行波段； 以及
所述多个滤波器中的至少一个， 其在从所述升级光线路终端端口到将所 述基础波段的下行波段和所述升级波段的下行波段的光信号复用的滤波器的 下行光通道上的透射波段包含所述升级波段的下行波段， 且反射波段包含所 述基础波段的下行波段。
3、 如权利要求 2所述的波分复用器， 其中，
所述多个滤波器中的任一个包括透射端、 反射端和公共端或透射端和公 共端， 所述反射端和公共端在所述任一个滤波器的一侧， 所述透射端在所述 任一个滤波器的与所述反射端和公共端所在的不同的一侧；
所述波分复用器包括第一滤波器、 第二滤波器、 第三滤波器和第四滤波 器， 且设置为： 在所述升级光线路终端端口与所述第一滤波器的公共端之间， 所述第一滤波器的反射端与所述第四滤波器的透射端或公共端之间， 所述第 四滤波器的公共端或透射端与所述第三滤波器的反射端之间， 所述第一滤波 器的透射端与所述第二滤波器的反射端之间， 所述遗留光线路终端端口与所 述第二滤波器的透射端之间， 所述第二滤波器的公共端与所述第三滤波器的 透射端之间， 以及所述波分复用器的公共端口与所述第三滤波器的公共端之 间存在光通道。
4、 如权利要求 3所述的波分复用器， 其中，
所述第一滤波器为带通或边带滤波器， 所述第一滤波器的透射波段包括 所述升级波段的下行波段， 反射波段包括所述升级波段的上行波段和所述基 础波段； 所述第二滤波器为边带滤波器， 所述第二滤波器的透射波段包括所 述升级波段的上行波段和所述基础波段， 反射波段包括所述升级波段的下行 波段； 所述第三滤波器为边带滤波器， 所述第三滤波器的透射波段包括所述 升级波段的下行波段和所述基础波段， 反射波段包括所述升级波段的上行波 段； 所述第四滤波器为带通或边带滤波器， 所述第四滤波器的透射波段包括 升级波段的上行波段， 反射波段包括升级波段的下行波段和基础波段； 或者 所述第一滤波器为带通或边带滤波器， 所述第一滤波器的透射波段包括 升级波段的上行波段， 反射波段包括升级波段的下行波段和基础波段； 所述 第二滤波器为边带滤波器， 所述第二滤波器的透射波段包括升级波段的下行 波段和基础波段， 反射波段包括升级波段的上行波段； 所述第三滤波器为边 带滤波器，所述第三滤波器的透射滤波包括升级波段的上行波段和基础波段， 反射波段包括升级波段的下行波段； 所述第四滤波器为带通或边带滤波器， 所述第四滤波器的透射波段包括升级波段的下行波段， 反射波段包括基础波 段和升级滤波和上行波段。
5、 如权利要求 2所述的波分复用器， 其中，
所述多个滤波器中的任一个包括透射端、 反射端和公共端或透射端和公 共端， 所述反射端和公共端在所述任一个滤波器的一侧， 所述透射端在所述 任一个滤波器的与所述反射端和公共端所在的不同的一侧；
所述波分复用器包括第一滤波器、 第二滤波器、 第三滤波器和第四滤波 器， 且设置为： 在所述升级光线路终端端口与所述第一滤波器的公共端之间， 所述第一滤波器的反射端与所述第三滤波器的透射端之间， 所述第一滤波器 的透射端与所述第二滤波器的反射端之间， 所述第二滤波器的透射端与所述 第四滤波器的透射端或公共端之间， 所述第二滤波器的公共端与所述第三滤 波器的反射端之间， 所述第三滤波器的公共端与所述波分复用器的公共端口 之间， 以及所述第四滤波器的公共端或透射端与所述遗留光线路终端端口之 间存在光通道。
6、 如权利要求 5所述的波分复用器， 其中，
所述第一滤波器为带通或边带滤波器， 所述第一滤波器的透射波段包括 升级波段的下行波段， 反射波段包括升级波段的上行波段和基础波段； 所述 第二滤波器为边带滤波器， 所述第二滤波器的透射波段包括升级波段的上行 波段和基础波段， 反射波段包括升级波段的下行波段； 所述第三滤波器为带 通或边带滤波器， 所述第三滤波器的透射波段包括升级波段的上行波段， 反 射波段包括升级波段的下行波段和基础波段； 所述第四滤波器为边带滤波器， 所述第四滤波器的透射波段包括升级波段的下行波段和基础波段， 反射波段 包括升级波段的上行波段； 或者
所述第一滤波器为带通或边带滤波器， 所述第一滤波器的透射波段包括 升级波段的上行波段， 反射波段包括升级波段的下行波段和基础波段； 所述 第二滤波器为边带滤波器， 所述第二滤波器的透射波段包括升级波段的下行 波段和基础波段， 反射波段包括升级波段的上行波段； 所述第三滤波器为带 通或边带滤波器， 所述第三滤波器的透射波段包括升级波段的下行波段， 反 射波段包括升级波段的上行波段和基础波段； 所述第四滤波器为边带滤波器， 所述第四滤波器的透射波段包括升级波段的上行波段和基础波段， 反射波段 包括升级波段的下行波段。
7、 如权利要求 2所述的波分复用器， 其中，
所述多个滤波器中的任一个包括透射端、 反射端和公共端或透射端和公 共端， 所述反射端和公共端在所述任一个滤波器的一侧， 所述透射端在所述 任一个滤波器的与所述反射端和公共端所在的不同的一侧；
所述波分复用器包括第一滤波器、 第二滤波器、 第三滤波器和第四滤波 器， 且设置为： 在所述升级光线路终端端口与所述第一滤波器的公共端之间， 所述第一滤波器的反射端与所述第二滤波器的透射端或公共端之间， 所述第 一滤波器的透射端与所述第四滤波器的反射端之间， 所述第二滤波器的公共 端或透射端与所述第三滤波器的反射端之间， 所述第三滤波器的公共端与所 述第四滤波器的透射端之间， 所述第三滤波器的透射端与所述遗留光线路终 端端口之间， 以及所述第四滤波器的公共端与所述波分复用器的公共端口之 间存在光通道。
8、 如权利要求 7所述的波分复用器， 其中，
所述第一滤波器为带通或边带滤波器， 所述第一滤波器的透射波段包括 升级波段的上行波段， 反射波段包括升级波段的下行波段和基础波段； 所述 第二滤波器为带通或边带滤波器， 所述第二滤波器的透射波段包括升级波段 的下行波段， 反射波段包括升级波段的上行波段和基础波段； 所述第三滤波 器为带通或边带滤波器， 所述第三滤波器的透射波段包括升级波段的上行波 段和基础波段， 反射波段包括升级波段的下行波段； 所述第四滤波器为边带 滤波器， 所述第四滤波器的透射波段包括升级波段的下行波段和基础波段， 反射波段包括升级波段的上行波段； 或者
所述第一滤波器为带通或边带滤波器， 所述第一滤波器的透射波段包括 升级波段的下行波段， 反射波段包括升级波段的上行波段和基础波段； 所述 第二滤波器为带通或边带滤波器， 所述第二滤波器的透射波段包括升级波段 的上行波段， 反射波段包括升级波段的下行波段和基础波段； 所述第三滤波 器为边带滤波器， 所述第三滤波器的透射波段包括升级波段的下行波段和基 础波段，反射波段包括升级波段的上行波段； 所述第四滤波器为边带滤波器， 所述第四滤波器的透射波段包括升级波段的上行波段和基础波段， 反射波段 包括升级波段的下行波段。
9、 如权利要求 1所述的波分复用器，
所述波分复用器包括一个滤波器， 且所述一个滤波器为带通滤波器， 所 述带通滤波器的透射端与所述遗留光线路终端端口之间， 所述带通滤波器的 公共端与所述波分复用器的公共端口之间， 以及所述带通滤波器的反射端与 所述升级光线路终端端口之间具有光通道； 且所述带通滤波器的透射波段包 括所述基础波段， 反射波段包括所述升级波段； 或者
所述带通滤波器的透射端与所述升级光线路终端端口之间， 所述带通滤 波器的公共端与所述波分复用器的公共端口之间， 以及所述带通滤波器的反 射端与所述遗留光线路终端端口之间具有光通道， 且所述带通滤波器的透射 波段包括所述升级波段， 反射波段包括所述基础波段。
10、 如权利要求 2所述的波分复用器， 其中， 所述波分复用器中的多个 滤波器的构成及所述多个滤波器的光谱特性为以下几种方式中的一种：
第一种方式， 所述波分复用器包括第一滤波器、 第二滤波器和第三滤波 器， 所述第一滤波器的透射波段包括所述升级波段的下行波段， 反射波段包 括所述升级波段的上行波段和所述基础波段； 所述第二滤波器的透射波段包 括所述升级波段的上行波段， 反射波段包括所述升级波段的下行波段和基础 波段； 所述第三滤波器的透射波段包括所述基础波段， 反射波段包括所述升 级波段； 连接上， 在所述升级光线路终端端口与所述第一滤波器的公共端之 间， 所述第一滤波器的反射端与所述第二滤波器的透射端之间， 所述第一滤 波器的透射端与所述第二滤波器的反射端之间， 所述第二滤波器的公共端与 所述第三滤波器的反射端之间， 所述第三滤波器的透射端与所述遗留光线路 终端端口之间， 以及所述第三滤波器的公共端与所述波分复用器的公共端口 之间存在光通道；
第二种方式，将所述第一种方式中的第一滤波器和第二滤波器位置互换， 并且保持所述第一种方式中的各滤波器的光谱特性不变； 第三种方式， 所述波分复用器包括第五滤波器和第六滤波器， 第五滤波 器的透射波段包括所述基础波段， 反射波段包括所述升级波段； 所述第六滤 波器的透射波段包括所述升级波段， 反射波段包括所述基础波段； 连接上， 所述遗留光线路终端端口与所述第五滤波器的透射端之间， 所述波分复用器 的公共端口与所述第五滤波器的公共端之间， 所述升级光线路终端端口与所 述第六滤波器的透射端或公共端之间， 以及所述第六滤波器的公共端或透射 端与所述第五滤波器的反射端之间存在光通道；
第四种方式， 所述波分复用器包括七滤波器和第八滤波器， 所述第七滤 波的透射波段包括所述升级波段， 反射波段包括所述基础波段片； 所述第八 滤波器的透射波段包括所述基础波段， 反射波段包括所述升级波段； 连接上， 所述第七滤波器的透射端与所述升级光线路终端端口之间， 所述第七滤波器 的反射端与所述第八滤波器的透射端或公共端之间， 所述第七滤波器的公共 端与所述波分复用器的公共端之间， 以及所述第八滤波器的公共端或透射端 与所述遗留光线路终端端口之间存在光通道；
第五种方式， 所述波分复用器包括第九滤波器、 所述第十滤波器和所述 第十一滤波器， 所述第九滤波器的透射波段包括所述升级波段， 反射波段包 括所述基础波段； 所述第十滤波器的透射波段包括所述升级波段的上行波段 和所述基础波段， 所述反射波段包括所述升级波段的下行波段； 所述第十一 滤波器的透射波段包括所述升级波段的下行波段和所述基础波段， 反射波段 包括所述升级波段的上行波段； 连接上， 在第九滤波器的透射端与升级光线 路终端端口之间， 第九滤波器的公共端与所述波分复用器的公共端之间， 所 述第九滤波器的反射端与所述第十滤波器的公共端或透射端之间， 第十滤波 器的透射端或公共端与第九滤波器的公共端或透射端之间， 以及第九滤波器 的透射端或公共端与遗留光线路终端端口之间存在光通道；
第六种方式， 将所述第五种方式中的第十滤波器和第十一滤波器位置互 换 , 并保持所述第五种方式中的各滤波器的光谱特性不变。
11、 如权利要求 1至 10中任一项所述的波分复用器， 其中， 所述波分复 用器中的滤波器均为薄膜滤波片。
12、 如权利要求 1至 10中任一项所述的波分复用器， 其中， 所述升级波段的上行波段为从 1260 nm至 1280 nm的波段， 所述升级波 段的下行波段为从 1550匪至 1580匪的波段； 所述基础波段的上行波段为从 1290 nm至 1330 nm的波段也即 O波段， 所述基础波段的下行波段为从 1480 匪至 1500匪的波段也即 S波段。
PCT/CN2009/074200 2009-04-21 2009-09-24 一种兼容两种无源光网络的波分复用器 WO2010121463A1 (zh)

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